diff --git a/anymail/tests/__init__.py b/anymail/tests/__init__.py
index 1fdab19..d1d80a3 100644
--- a/anymail/tests/__init__.py
+++ b/anymail/tests/__init__.py
@@ -2,10 +2,17 @@
 # is required by the old (<=1.5) DjangoTestSuiteRunner.
 
 from .test_mailgun_backend import *
+from .test_mailgun_integration import *
 
+from .test_mandrill_backend import *
 from .test_mandrill_integration import *
-from .test_mandrill_send import *
-from .test_mandrill_send_template import *
-from .test_mandrill_session_sharing import *
-from .test_mandrill_subaccounts import *
+
+from .test_postmark_backend import *
+from .test_postmark_integration import *
+
+from .test_sendgrid_backend import *
+from .test_sendgrid_integration import *
+
+# Djrill leftovers:
+from .test_mandrill_djrill_features import *
 from .test_mandrill_webhook import *
diff --git a/anymail/tests/mock_backend.py b/anymail/tests/mock_backend.py
deleted file mode 100644
index fd001fd..0000000
--- a/anymail/tests/mock_backend.py
+++ /dev/null
@@ -1,72 +0,0 @@
-import json
-import requests
-import six
-from mock import patch
-
-from django.test import TestCase
-from django.test.utils import override_settings
-
-
-MANDRILL_SUCCESS_RESPONSE = b"""[{
-    "email": "to@example.com",
-    "status": "sent",
-    "_id": "abc123",
-    "reject_reason": null
-}]"""
-
-
-@override_settings(MANDRILL_API_KEY="FAKE_API_KEY_FOR_TESTING",
-                   EMAIL_BACKEND="anymail.backends.mandrill.MandrillBackend")
-class DjrillBackendMockAPITestCase(TestCase):
-    """TestCase that uses Djrill EmailBackend with a mocked Mandrill API"""
-
-    class MockResponse(requests.Response):
-        """requests.post return value mock sufficient for MandrillBackend"""
-        def __init__(self, status_code=200, raw=MANDRILL_SUCCESS_RESPONSE, encoding='utf-8'):
-            super(DjrillBackendMockAPITestCase.MockResponse, self).__init__()
-            self.status_code = status_code
-            self.encoding = encoding
-            self.raw = six.BytesIO(raw)
-
-    def setUp(self):
-        self.patch = patch('requests.Session.request', autospec=True)
-        self.mock_post = self.patch.start()
-        self.mock_post.return_value = self.MockResponse()
-
-    def tearDown(self):
-        self.patch.stop()
-
-    def assert_mandrill_called(self, endpoint):
-        """Verifies the (mock) Mandrill API was called on endpoint.
-
-        endpoint is a Mandrill API, e.g., "/messages/send.json"
-        """
-        # This assumes the last (or only) call to requests.post is the
-        # Mandrill API call of interest.
-        if self.mock_post.call_args is None:
-            raise AssertionError("Mandrill API was not called")
-        (args, kwargs) = self.mock_post.call_args
-        try:
-            post_url = kwargs.get('url', None) or args[2]
-        except IndexError:
-            raise AssertionError("requests.Session.request was called without an url (?!)")
-        if not post_url.endswith(endpoint):
-            raise AssertionError(
-                "requests.post was not called on %s\n(It was called on %s)"
-                % (endpoint, post_url))
-
-    def get_api_call_data(self):
-        """Returns the data posted to the Mandrill API.
-
-        Fails test if API wasn't called.
-        """
-        if self.mock_post.call_args is None:
-            raise AssertionError("Mandrill API was not called")
-        (args, kwargs) = self.mock_post.call_args
-        try:
-            post_data = kwargs.get('data', None) or args[4]
-        except IndexError:
-            raise AssertionError("requests.Session.request was called without data")
-        return json.loads(post_data)
-
-
diff --git a/anymail/tests/mock_requests_backend.py b/anymail/tests/mock_requests_backend.py
index 1f5781f..a18c572 100644
--- a/anymail/tests/mock_requests_backend.py
+++ b/anymail/tests/mock_requests_backend.py
@@ -1,10 +1,13 @@
 import json
 
+from django.core import mail
 from django.test import SimpleTestCase
 import requests
 import six
 from mock import patch
 
+from anymail.exceptions import AnymailAPIError
+
 from .utils import AnymailTestMixin
 
 UNSET = object()
@@ -25,9 +28,9 @@ class RequestsBackendMockAPITestCase(SimpleTestCase, AnymailTestMixin):
 
     def setUp(self):
         super(RequestsBackendMockAPITestCase, self).setUp()
-        self.patch = patch('requests.Session.request', autospec=True)
-        self.mock_request = self.patch.start()
-        self.addCleanup(self.patch.stop)
+        self.patch_request = patch('requests.Session.request', autospec=True)
+        self.mock_request = self.patch_request.start()
+        self.addCleanup(self.patch_request.stop)
         self.set_mock_response()
 
     def set_mock_response(self, status_code=200, raw=UNSET, encoding='utf-8'):
@@ -101,3 +104,73 @@ class RequestsBackendMockAPITestCase(SimpleTestCase, AnymailTestMixin):
     def assert_esp_not_called(self, msg=None):
         if self.mock_request.called:
             raise AssertionError(msg or "ESP API was called and shouldn't have been")
+
+
+# noinspection PyUnresolvedReferences
+class SessionSharingTestCasesMixin(object):
+    """Mixin that tests connection sharing in any RequestsBackendMockAPITestCase
+
+    (Contains actual test cases, so can't be included in RequestsBackendMockAPITestCase
+    itself, as that would re-run these tests several times for each backend, in
+    each TestCase for the backend.)
+    """
+
+    def setUp(self):
+        super(SessionSharingTestCasesMixin, self).setUp()
+        self.patch_close = patch('requests.Session.close', autospec=True)
+        self.mock_close = self.patch_close.start()
+        self.addCleanup(self.patch_close.stop)
+
+    def test_connection_sharing(self):
+        """RequestsBackend reuses one requests session when sending multiple messages"""
+        datatuple = (
+            ('Subject 1', 'Body 1', 'from@example.com', ['to@example.com']),
+            ('Subject 2', 'Body 2', 'from@example.com', ['to@example.com']),
+        )
+        mail.send_mass_mail(datatuple)
+        self.assertEqual(self.mock_request.call_count, 2)
+        session1 = self.mock_request.call_args_list[0][0]  # arg[0] (self) is session
+        session2 = self.mock_request.call_args_list[1][0]
+        self.assertEqual(session1, session2)
+        self.assertEqual(self.mock_close.call_count, 1)
+
+    def test_caller_managed_connections(self):
+        """Calling code can created long-lived connection that it opens and closes"""
+        connection = mail.get_connection()
+        connection.open()
+        mail.send_mail('Subject 1', 'body', 'from@example.com', ['to@example.com'], connection=connection)
+        session1 = self.mock_request.call_args[0]
+        self.assertEqual(self.mock_close.call_count, 0)  # shouldn't be closed yet
+
+        mail.send_mail('Subject 2', 'body', 'from@example.com', ['to@example.com'], connection=connection)
+        self.assertEqual(self.mock_close.call_count, 0)  # still shouldn't be closed
+        session2 = self.mock_request.call_args[0]
+        self.assertEqual(session1, session2)  # should have reused same session
+
+        connection.close()
+        self.assertEqual(self.mock_close.call_count, 1)
+
+    def test_session_closed_after_exception(self):
+        self.set_mock_response(status_code=500)
+        with self.assertRaises(AnymailAPIError):
+            mail.send_mail('Subject', 'Message', 'from@example.com', ['to@example.com'])
+        self.assertEqual(self.mock_close.call_count, 1)
+
+    def test_session_closed_after_fail_silently_exception(self):
+        self.set_mock_response(status_code=500)
+        sent = mail.send_mail('Subject', 'Message', 'from@example.com', ['to@example.com'],
+                              fail_silently=True)
+        self.assertEqual(sent, 0)
+        self.assertEqual(self.mock_close.call_count, 1)
+
+    def test_caller_managed_session_closed_after_exception(self):
+        connection = mail.get_connection()
+        connection.open()
+        self.set_mock_response(status_code=500)
+        with self.assertRaises(AnymailAPIError):
+            mail.send_mail('Subject', 'Message', 'from@example.com', ['to@example.com'],
+                           connection=connection)
+        self.assertEqual(self.mock_close.call_count, 0)  # wait for us to close it
+
+        connection.close()
+        self.assertEqual(self.mock_close.call_count, 1)
diff --git a/anymail/tests/test_mailgun_backend.py b/anymail/tests/test_mailgun_backend.py
index 74eb2fb..f272b26 100644
--- a/anymail/tests/test_mailgun_backend.py
+++ b/anymail/tests/test_mailgun_backend.py
@@ -16,7 +16,7 @@ from django.utils.timezone import get_fixed_timezone, override as override_curre
 from anymail.exceptions import AnymailAPIError, AnymailSerializationError, AnymailUnsupportedFeature
 from anymail.message import attach_inline_image_file
 
-from .mock_requests_backend import RequestsBackendMockAPITestCase
+from .mock_requests_backend import RequestsBackendMockAPITestCase, SessionSharingTestCasesMixin
 from .utils import sample_image_content, sample_image_path, SAMPLE_IMAGE_FILENAME, AnymailTestMixin
 
 
@@ -439,6 +439,11 @@ class MailgunBackendRecipientsRefusedTests(MailgunBackendMockAPITestCase):
         self.assertEqual(sent, 0)
 
 
+class MailgunBackendSessionSharingTestCase(SessionSharingTestCasesMixin, MailgunBackendMockAPITestCase):
+    """Requests session sharing tests"""
+    pass  # tests are defined in the mixin
+
+
 @override_settings(ANYMAIL_SEND_DEFAULTS={
     'metadata': {'global': 'globalvalue', 'other': 'othervalue'},
     'tags': ['globaltag'],
diff --git a/anymail/tests/test_mandrill_backend.py b/anymail/tests/test_mandrill_backend.py
new file mode 100644
index 0000000..280fbac
--- /dev/null
+++ b/anymail/tests/test_mandrill_backend.py
@@ -0,0 +1,538 @@
+# -*- coding: utf-8 -*-
+
+from __future__ import unicode_literals
+
+import unittest
+from datetime import date, datetime
+from decimal import Decimal
+from email.mime.base import MIMEBase
+from email.mime.image import MIMEImage
+
+from django.core import mail
+from django.core.exceptions import ImproperlyConfigured
+from django.test import SimpleTestCase
+from django.test.utils import override_settings
+from django.utils.timezone import get_fixed_timezone, override as override_current_timezone
+
+from anymail.exceptions import (AnymailAPIError, AnymailRecipientsRefused,
+                                AnymailSerializationError, AnymailUnsupportedFeature)
+from anymail.message import attach_inline_image
+
+from .mock_requests_backend import RequestsBackendMockAPITestCase, SessionSharingTestCasesMixin
+from .utils import sample_image_content, sample_image_path, SAMPLE_IMAGE_FILENAME, AnymailTestMixin, decode_att
+
+
+@override_settings(EMAIL_BACKEND='anymail.backends.mandrill.MandrillBackend',
+                   ANYMAIL={'MANDRILL_API_KEY': 'test_api_key'})
+class MandrillBackendMockAPITestCase(RequestsBackendMockAPITestCase):
+    DEFAULT_RAW_RESPONSE = b"""[{
+        "email": "to@example.com",
+        "status": "sent",
+        "_id": "abc123",
+        "reject_reason": null
+    }]"""
+
+    def setUp(self):
+        super(MandrillBackendMockAPITestCase, self).setUp()
+        # Simple message useful for many tests
+        self.message = mail.EmailMultiAlternatives('Subject', 'Text Body', 'from@example.com', ['to@example.com'])
+
+
+class MandrillBackendStandardEmailTests(MandrillBackendMockAPITestCase):
+    """Test backend support for Django mail wrappers"""
+
+    def test_send_mail(self):
+        mail.send_mail('Subject here', 'Here is the message.',
+                       'from@example.com', ['to@example.com'], fail_silently=False)
+        self.assert_esp_called("/messages/send.json")
+        data = self.get_api_call_json()
+        self.assertEqual(data['key'], "test_api_key")
+        self.assertEqual(data['message']['subject'], "Subject here")
+        self.assertEqual(data['message']['text'], "Here is the message.")
+        self.assertNotIn('from_name', data['message'])
+        self.assertEqual(data['message']['from_email'], "from@example.com")
+        self.assertEqual(data['message']['to'], [{'email': 'to@example.com', 'name': '', 'type': 'to'}])
+
+    def test_name_addr(self):
+        """Make sure RFC2822 name-addr format (with display-name) is allowed
+
+        (Test both sender and recipient addresses)
+        """
+        msg = mail.EmailMessage(
+            'Subject', 'Message',
+            'From Name <from@example.com>',
+            ['Recipient #1 <to1@example.com>', 'to2@example.com'],
+            cc=['Carbon Copy <cc1@example.com>', 'cc2@example.com'],
+            bcc=['Blind Copy <bcc1@example.com>', 'bcc2@example.com'])
+        msg.send()
+        data = self.get_api_call_json()
+        self.assertEqual(data['message']['from_name'], "From Name")
+        self.assertEqual(data['message']['from_email'], "from@example.com")
+        self.assertEqual(data['message']['to'], [
+            {'email': 'to1@example.com', 'name': 'Recipient #1', 'type': 'to'},
+            {'email': 'to2@example.com', 'name': '', 'type': 'to'},
+            {'email': 'cc1@example.com', 'name': 'Carbon Copy', 'type': 'cc'},
+            {'email': 'cc2@example.com', 'name': '', 'type': 'cc'},
+            {'email': 'bcc1@example.com', 'name': 'Blind Copy', 'type': 'bcc'},
+            {'email': 'bcc2@example.com', 'name': '', 'type': 'bcc'},
+        ])
+
+    def test_email_message(self):
+        email = mail.EmailMessage(
+            'Subject', 'Body goes here',
+            'from@example.com',
+            ['to1@example.com', 'Also To <to2@example.com>'],
+            bcc=['bcc1@example.com', 'Also BCC <bcc2@example.com>'],
+            cc=['cc1@example.com', 'Also CC <cc2@example.com>'],
+            headers={'Reply-To': 'another@example.com',
+                     'X-MyHeader': 'my value',
+                     'Message-ID': 'mycustommsgid@example.com'})
+        email.send()
+        data = self.get_api_call_json()
+        self.assertEqual(data['message']['subject'], "Subject")
+        self.assertEqual(data['message']['text'], "Body goes here")
+        self.assertEqual(data['message']['from_email'], "from@example.com")
+        self.assertEqual(data['message']['headers'],
+                         {'Reply-To': 'another@example.com',
+                          'X-MyHeader': 'my value',
+                          'Message-ID': 'mycustommsgid@example.com'})
+        # Verify recipients correctly identified as "to", "cc", or "bcc"
+        self.assertEqual(data['message']['to'], [
+            {'email': 'to1@example.com', 'name': '', 'type': 'to'},
+            {'email': 'to2@example.com', 'name': 'Also To', 'type': 'to'},
+            {'email': 'cc1@example.com', 'name': '', 'type': 'cc'},
+            {'email': 'cc2@example.com', 'name': 'Also CC', 'type': 'cc'},
+            {'email': 'bcc1@example.com', 'name': '', 'type': 'bcc'},
+            {'email': 'bcc2@example.com', 'name': 'Also BCC', 'type': 'bcc'},
+        ])
+        # Don't use Mandrill's bcc_address "logging" feature for bcc's:
+        self.assertNotIn('bcc_address', data['message'])
+
+    def test_html_message(self):
+        text_content = 'This is an important message.'
+        html_content = '<p>This is an <strong>important</strong> message.</p>'
+        email = mail.EmailMultiAlternatives('Subject', text_content,
+                                            'from@example.com', ['to@example.com'])
+        email.attach_alternative(html_content, "text/html")
+        email.send()
+        data = self.get_api_call_json()
+        self.assertEqual(data['message']['text'], text_content)
+        self.assertEqual(data['message']['html'], html_content)
+        # Don't accidentally send the html part as an attachment:
+        self.assertFalse('attachments' in data['message'])
+
+    def test_html_only_message(self):
+        html_content = '<p>This is an <strong>important</strong> message.</p>'
+        email = mail.EmailMessage('Subject', html_content,
+                                  'from@example.com', ['to@example.com'])
+        email.content_subtype = "html"  # Main content is now text/html
+        email.send()
+        data = self.get_api_call_json()
+        self.assertNotIn('text', data['message'])
+        self.assertEqual(data['message']['html'], html_content)
+
+    def test_reply_to(self):
+        # reply_to is new in Django 1.8 -- before that, you can simply include it in headers
+        try:
+            # noinspection PyArgumentList
+            email = mail.EmailMessage('Subject', 'Body goes here', 'from@example.com', ['to1@example.com'],
+                                      reply_to=['reply@example.com', 'Other <reply2@example.com>'],
+                                      headers={'X-Other': 'Keep'})
+        except TypeError:
+            # Pre-Django 1.8
+            raise unittest.SkipTest("Django version doesn't support EmailMessage(reply_to)")
+        email.send()
+        data = self.get_api_call_json()
+        self.assertEqual(data['message']['headers']['Reply-To'],
+                         'reply@example.com, Other <reply2@example.com>')
+        self.assertEqual(data['message']['headers']['X-Other'], 'Keep')  # don't lose other headers
+
+    def test_attachments(self):
+        text_content = "* Item one\n* Item two\n* Item three"
+        self.message.attach(filename="test.txt", content=text_content, mimetype="text/plain")
+
+        # Should guess mimetype if not provided...
+        png_content = b"PNG\xb4 pretend this is the contents of a png file"
+        self.message.attach(filename="test.png", content=png_content)
+
+        # Should work with a MIMEBase object (also tests no filename)...
+        pdf_content = b"PDF\xb4 pretend this is valid pdf data"
+        mimeattachment = MIMEBase('application', 'pdf')
+        mimeattachment.set_payload(pdf_content)
+        self.message.attach(mimeattachment)
+
+        self.message.send()
+        data = self.get_api_call_json()
+        attachments = data['message']['attachments']
+        self.assertEqual(len(attachments), 3)
+        self.assertEqual(attachments[0]["type"], "text/plain")
+        self.assertEqual(attachments[0]["name"], "test.txt")
+        self.assertEqual(decode_att(attachments[0]["content"]).decode('ascii'), text_content)
+        self.assertEqual(attachments[1]["type"], "image/png")  # inferred from filename
+        self.assertEqual(attachments[1]["name"], "test.png")
+        self.assertEqual(decode_att(attachments[1]["content"]), png_content)
+        self.assertEqual(attachments[2]["type"], "application/pdf")
+        self.assertEqual(attachments[2]["name"], "")  # none
+        self.assertEqual(decode_att(attachments[2]["content"]), pdf_content)
+        # Make sure the image attachment is not treated as embedded:
+        self.assertFalse('images' in data['message'])
+
+    def test_unicode_attachment_correctly_decoded(self):
+        # Slight modification from the Django unicode docs:
+        # http://django.readthedocs.org/en/latest/ref/unicode.html#email
+        self.message.attach("Une pièce jointe.html", '<p>\u2019</p>', mimetype='text/html')
+        self.message.send()
+        data = self.get_api_call_json()
+        attachments = data['message']['attachments']
+        self.assertEqual(len(attachments), 1)
+
+    def test_embedded_images(self):
+        image_data = sample_image_content()  # Read from a png file
+
+        cid = attach_inline_image(self.message, image_data)
+        html_content = '<p>This has an <img src="cid:%s" alt="inline" /> image.</p>' % cid
+        self.message.attach_alternative(html_content, "text/html")
+
+        self.message.send()
+        data = self.get_api_call_json()
+        self.assertEqual(len(data['message']['images']), 1)
+        self.assertEqual(data['message']['images'][0]["type"], "image/png")
+        self.assertEqual(data['message']['images'][0]["name"], cid)
+        self.assertEqual(decode_att(data['message']['images'][0]["content"]), image_data)
+        # Make sure neither the html nor the inline image is treated as an attachment:
+        self.assertFalse('attachments' in data['message'])
+
+    def test_attached_images(self):
+        image_filename = SAMPLE_IMAGE_FILENAME
+        image_path = sample_image_path(image_filename)
+        image_data = sample_image_content(image_filename)
+
+        self.message.attach_file(image_path)  # option 1: attach as a file
+
+        image = MIMEImage(image_data)  # option 2: construct the MIMEImage and attach it directly
+        self.message.attach(image)
+
+        self.message.send()
+        data = self.get_api_call_json()
+        attachments = data['message']['attachments']
+        self.assertEqual(len(attachments), 2)
+        self.assertEqual(attachments[0]["type"], "image/png")
+        self.assertEqual(attachments[0]["name"], image_filename)
+        self.assertEqual(decode_att(attachments[0]["content"]), image_data)
+        self.assertEqual(attachments[1]["type"], "image/png")
+        self.assertEqual(attachments[1]["name"], "")  # unknown -- not attached as file
+        self.assertEqual(decode_att(attachments[1]["content"]), image_data)
+        # Make sure the image attachments are not treated as embedded:
+        self.assertFalse('images' in data['message'])
+
+    def test_multiple_html_alternatives(self):
+        # Multiple alternatives not allowed
+        self.message.attach_alternative("<p>First html is OK</p>", "text/html")
+        self.message.attach_alternative("<p>But not second html</p>", "text/html")
+        with self.assertRaises(AnymailUnsupportedFeature):
+            self.message.send()
+
+    def test_html_alternative(self):
+        # Only html alternatives allowed
+        self.message.attach_alternative("{'not': 'allowed'}", "application/json")
+        with self.assertRaises(AnymailUnsupportedFeature):
+            self.message.send()
+
+    def test_alternatives_fail_silently(self):
+        # Make sure fail_silently is respected
+        self.message.attach_alternative("{'not': 'allowed'}", "application/json")
+        sent = self.message.send(fail_silently=True)
+        self.assert_esp_not_called("API should not be called when send fails silently")
+        self.assertEqual(sent, 0)
+
+    def test_api_failure(self):
+        self.set_mock_response(status_code=400)
+        with self.assertRaises(AnymailAPIError):
+            sent = mail.send_mail('Subject', 'Body', 'from@example.com', ['to@example.com'])
+            self.assertEqual(sent, 0)
+
+        # Make sure fail_silently is respected
+        self.set_mock_response(status_code=400)
+        sent = mail.send_mail('Subject', 'Body', 'from@example.com', ['to@example.com'],
+                              fail_silently=True)
+        self.assertEqual(sent, 0)
+
+    def test_api_error_includes_details(self):
+        """AnymailAPIError should include ESP's error message"""
+        self.set_mock_response(status_code=400, raw=b"""{
+             "status": "error",
+             "code": 12,
+             "name": "Error_Name",
+             "message": "Helpful explanation from Mandrill"
+        }""")
+        with self.assertRaisesMessage(AnymailAPIError, "Helpful explanation from Mandrill"):
+            self.message.send()
+
+        # Non-JSON error response:
+        self.set_mock_response(status_code=500, raw=b"Invalid API key")
+        with self.assertRaisesMessage(AnymailAPIError, "Invalid API key"):
+            self.message.send()
+
+        # No content in the error response:
+        self.set_mock_response(status_code=502, raw=None)
+        with self.assertRaises(AnymailAPIError):
+            self.message.send()
+
+
+class MandrillBackendAnymailFeatureTests(MandrillBackendMockAPITestCase):
+    """Test backend support for Anymail added features"""
+
+    def test_metadata(self):
+        self.message.metadata = {'user_id': "12345", 'items': 6}
+        self.message.send()
+        data = self.get_api_call_json()
+        self.assertEqual(data['message']['metadata'], {'user_id': "12345", 'items': 6})
+
+    def test_send_at(self):
+        utc_plus_6 = get_fixed_timezone(6 * 60)
+        utc_minus_8 = get_fixed_timezone(-8 * 60)
+
+        with override_current_timezone(utc_plus_6):
+            # Timezone-naive datetime assumed to be Django current_timezone
+            self.message.send_at = datetime(2022, 10, 11, 12, 13, 14, 567)
+            self.message.send()
+            data = self.get_api_call_json()
+            self.assertEqual(data['send_at'], "2022-10-11 06:13:14")  # 12:13 UTC+6 == 06:13 UTC
+
+            # Timezone-aware datetime converted to UTC:
+            self.message.send_at = datetime(2016, 3, 4, 5, 6, 7, tzinfo=utc_minus_8)
+            self.message.send()
+            data = self.get_api_call_json()
+            self.assertEqual(data['send_at'], "2016-03-04 13:06:07")  # 05:06 UTC-8 == 13:06 UTC
+
+            # Date-only treated as midnight in current timezone
+            self.message.send_at = date(2022, 10, 22)
+            self.message.send()
+            data = self.get_api_call_json()
+            self.assertEqual(data['send_at'], "2022-10-21 18:00:00")  # 00:00 UTC+6 == 18:00-1d UTC
+
+            # POSIX timestamp
+            self.message.send_at = 1651820889  # 2022-05-06 07:08:09 UTC
+            self.message.send()
+            data = self.get_api_call_json()
+            self.assertEqual(data['send_at'], "2022-05-06 07:08:09")
+
+            # String passed unchanged (this is *not* portable between ESPs)
+            self.message.send_at = "2013-11-12 01:02:03"
+            self.message.send()
+            data = self.get_api_call_json()
+            self.assertEqual(data['send_at'], "2013-11-12 01:02:03")
+
+    def test_tags(self):
+        self.message.tags = ["receipt", "repeat-user"]
+        self.message.send()
+        data = self.get_api_call_json()
+        self.assertEqual(data['message']['tags'], ["receipt", "repeat-user"])
+
+    def test_tracking(self):
+        # Test one way...
+        self.message.track_opens = True
+        self.message.track_clicks = False
+        self.message.send()
+        data = self.get_api_call_json()
+        self.assertEqual(data['message']['track_opens'], True)
+        self.assertEqual(data['message']['track_clicks'], False)
+
+        # ...and the opposite way
+        self.message.track_opens = False
+        self.message.track_clicks = True
+        self.message.send()
+        data = self.get_api_call_json()
+        self.assertEqual(data['message']['track_opens'], False)
+        self.assertEqual(data['message']['track_clicks'], True)
+
+    def test_default_omits_options(self):
+        """Make sure by default we don't send any ESP-specific options.
+
+        Options not specified by the caller should be omitted entirely from
+        the API call (*not* sent as False or empty). This ensures
+        that your ESP account settings apply by default.
+        """
+        self.message.send()
+        self.assert_esp_called("/messages/send.json")
+        data = self.get_api_call_json()
+        self.assertNotIn('metadata', data['message'])
+        self.assertNotIn('send_at', data)
+        self.assertNotIn('tags', data['message'])
+        self.assertNotIn('track_opens', data['message'])
+        self.assertNotIn('track_clicks', data['message'])
+
+    # noinspection PyUnresolvedReferences
+    def test_send_attaches_anymail_status(self):
+        """ The anymail_status should be attached to the message when it is sent """
+        response_content = b'[{"email": "to1@example.com", "status": "sent", "_id": "abc123"}]'
+        self.set_mock_response(raw=response_content)
+        msg = mail.EmailMessage('Subject', 'Message', 'from@example.com', ['to1@example.com'],)
+        sent = msg.send()
+        self.assertEqual(sent, 1)
+        self.assertEqual(msg.anymail_status.status, {'sent'})
+        self.assertEqual(msg.anymail_status.message_id, 'abc123')
+        self.assertEqual(msg.anymail_status.recipients['to1@example.com'].status, 'sent')
+        self.assertEqual(msg.anymail_status.recipients['to1@example.com'].message_id, 'abc123')
+        self.assertEqual(msg.anymail_status.esp_response.content, response_content)
+
+    # noinspection PyUnresolvedReferences
+    def test_send_failed_anymail_status(self):
+        """ If the send fails, anymail_status should contain initial values"""
+        self.set_mock_response(status_code=500)
+        sent = self.message.send(fail_silently=True)
+        self.assertEqual(sent, 0)
+        self.assertIsNone(self.message.anymail_status.status)
+        self.assertIsNone(self.message.anymail_status.message_id)
+        self.assertEqual(self.message.anymail_status.recipients, {})
+        self.assertIsNone(self.message.anymail_status.esp_response)
+
+    # noinspection PyUnresolvedReferences
+    def test_send_unparsable_response(self):
+        """If the send succeeds, but a non-JSON API response, should raise an API exception"""
+        mock_response = self.set_mock_response(status_code=200,
+                                               raw=b"yikes, this isn't a real response")
+        with self.assertRaises(AnymailAPIError):
+            self.message.send()
+        self.assertIsNone(self.message.anymail_status.status)
+        self.assertIsNone(self.message.anymail_status.message_id)
+        self.assertEqual(self.message.anymail_status.recipients, {})
+        self.assertEqual(self.message.anymail_status.esp_response, mock_response)
+
+    def test_json_serialization_errors(self):
+        """Try to provide more information about non-json-serializable data"""
+        self.message.metadata = {'total': Decimal('19.99')}
+        with self.assertRaises(AnymailSerializationError) as cm:
+            self.message.send()
+            print(self.get_api_call_data())
+        err = cm.exception
+        self.assertIsInstance(err, TypeError)  # compatibility with json.dumps
+        self.assertIn("Don't know how to send this data to Mandrill", str(err))  # our added context
+        self.assertIn("Decimal('19.99') is not JSON serializable", str(err))  # original message
+
+
+class MandrillBackendRecipientsRefusedTests(MandrillBackendMockAPITestCase):
+    """Should raise AnymailRecipientsRefused when *all* recipients are rejected or invalid"""
+
+    def test_recipients_refused(self):
+        msg = mail.EmailMessage('Subject', 'Body', 'from@example.com',
+                                ['invalid@localhost', 'reject@test.mandrillapp.com'])
+        self.set_mock_response(raw=b"""[
+            {"email": "invalid@localhost", "status": "invalid"},
+            {"email": "reject@test.mandrillapp.com", "status": "rejected"}
+        ]""")
+        with self.assertRaises(AnymailRecipientsRefused):
+            msg.send()
+
+    def test_fail_silently(self):
+        self.set_mock_response(raw=b"""[
+            {"email": "invalid@localhost", "status": "invalid"},
+            {"email": "reject@test.mandrillapp.com", "status": "rejected"}
+        ]""")
+        sent = mail.send_mail('Subject', 'Body', 'from@example.com',
+                              ['invalid@localhost', 'reject@test.mandrillapp.com'],
+                              fail_silently=True)
+        self.assertEqual(sent, 0)
+
+    def test_mixed_response(self):
+        """If *any* recipients are valid or queued, no exception is raised"""
+        msg = mail.EmailMessage('Subject', 'Body', 'from@example.com',
+                                ['invalid@localhost', 'valid@example.com',
+                                 'reject@test.mandrillapp.com', 'also.valid@example.com'])
+        self.set_mock_response(raw=b"""[
+            {"email": "invalid@localhost", "status": "invalid"},
+            {"email": "valid@example.com", "status": "sent"},
+            {"email": "reject@test.mandrillapp.com", "status": "rejected"},
+            {"email": "also.valid@example.com", "status": "queued"}
+        ]""")
+        sent = msg.send()
+        self.assertEqual(sent, 1)  # one message sent, successfully, to 2 of 4 recipients
+        status = msg.anymail_status
+        self.assertEqual(status.recipients['invalid@localhost'].status, 'invalid')
+        self.assertEqual(status.recipients['valid@example.com'].status, 'sent')
+        self.assertEqual(status.recipients['reject@test.mandrillapp.com'].status, 'rejected')
+        self.assertEqual(status.recipients['also.valid@example.com'].status, 'queued')
+
+    @override_settings(ANYMAIL_IGNORE_RECIPIENT_STATUS=True)
+    def test_settings_override(self):
+        """No exception with ignore setting"""
+        self.set_mock_response(raw=b"""[
+            {"email": "invalid@localhost", "status": "invalid"},
+            {"email": "reject@test.mandrillapp.com", "status": "rejected"}
+        ]""")
+        sent = mail.send_mail('Subject', 'Body', 'from@example.com',
+                              ['invalid@localhost', 'reject@test.mandrillapp.com'])
+        self.assertEqual(sent, 1)  # refused message is included in sent count
+
+
+class MandrillBackendSessionSharingTestCase(SessionSharingTestCasesMixin, MandrillBackendMockAPITestCase):
+    """Requests session sharing tests"""
+    pass  # tests are defined in the mixin
+
+
+@override_settings(ANYMAIL_SEND_DEFAULTS={
+    'metadata': {'global': 'globalvalue', 'other': 'othervalue'},
+    'tags': ['globaltag'],
+    'track_clicks': True,
+    'track_opens': True,
+    # 'esp_extra': {'globaloption': 'globalsetting'},  # Mandrill doesn't support esp_extra yet
+})
+class MandrillBackendSendDefaultsTests(MandrillBackendMockAPITestCase):
+    """Tests backend support for global SEND_DEFAULTS"""
+
+    def test_send_defaults(self):
+        """Test that global send defaults are applied"""
+        self.message.send()
+        data = self.get_api_call_json()
+        # All these values came from ANYMAIL_SEND_DEFAULTS:
+        self.assertEqual(data['message']['metadata'], {'global': 'globalvalue', 'other': 'othervalue'})
+        self.assertEqual(data['message']['tags'], ['globaltag'])
+        self.assertEqual(data['message']['track_clicks'], True)
+        self.assertEqual(data['message']['track_opens'], True)
+        # self.assertEqual(data['globaloption'], 'globalsetting')
+
+    def test_merge_message_with_send_defaults(self):
+        """Test that individual message settings are *merged into* the global send defaults"""
+        self.message.metadata = {'message': 'messagevalue', 'other': 'override'}
+        self.message.tags = ['messagetag']
+        self.message.track_clicks = False
+        # self.message.esp_extra = {'messageoption': 'messagesetting'}
+
+        self.message.send()
+        data = self.get_api_call_json()
+        # All these values came from ANYMAIL_SEND_DEFAULTS + message.*:
+        self.assertEqual(data['message']['metadata'],
+                         {'global': 'globalvalue', 'message': 'messagevalue', 'other': 'override'})  # merged
+        self.assertEqual(data['message']['tags'], ['globaltag', 'messagetag'])  # tags concatenated
+        self.assertEqual(data['message']['track_clicks'], False)  # message overrides
+        self.assertEqual(data['message']['track_opens'], True)
+        # self.assertEqual(data['globaloption'], 'globalsetting')
+        # self.assertEqual(data['messageoption'], 'messagesetting')  # additional esp_extra
+
+    @override_settings(ANYMAIL_MANDRILL_SEND_DEFAULTS={
+        'tags': ['esptag'],
+        'metadata': {'esp': 'espvalue'},
+        'track_opens': False,
+    })
+    def test_esp_send_defaults(self):
+        """Test that ESP-specific send defaults override individual global defaults"""
+        self.message.send()
+        data = self.get_api_call_json()
+        # All these values came from ANYMAIL_SEND_DEFAULTS plus ANYMAIL_MAILGUN_SEND_DEFAULTS:
+        self.assertEqual(data['message']['metadata'], {'esp': 'espvalue'})  # entire metadata overridden
+        self.assertEqual(data['message']['tags'], ['esptag'])  # entire tags overridden
+        self.assertEqual(data['message']['track_clicks'], True)  # we didn't override the global track_clicks
+        self.assertEqual(data['message']['track_opens'], False)
+        # self.assertEqual(data['globaloption'], 'globalsetting')  # we didn't override the global esp_extra
+
+
+@override_settings(EMAIL_BACKEND="anymail.backends.mandrill.MandrillBackend")
+class MandrillBackendImproperlyConfiguredTests(SimpleTestCase, AnymailTestMixin):
+    """Test backend without required settings"""
+
+    def test_missing_api_key(self):
+        with self.assertRaises(ImproperlyConfigured) as cm:
+            mail.send_mail('Subject', 'Message', 'from@example.com', ['to@example.com'])
+        errmsg = str(cm.exception)
+        self.assertRegex(errmsg, r'\bMANDRILL_API_KEY\b')
+        self.assertRegex(errmsg, r'\bANYMAIL_MANDRILL_API_KEY\b')
diff --git a/anymail/tests/test_mandrill_djrill_features.py b/anymail/tests/test_mandrill_djrill_features.py
new file mode 100644
index 0000000..50a9e8e
--- /dev/null
+++ b/anymail/tests/test_mandrill_djrill_features.py
@@ -0,0 +1,333 @@
+from datetime import date
+from django.core import mail
+from django.test import override_settings
+
+from anymail.exceptions import AnymailAPIError, AnymailSerializationError
+
+from .test_mandrill_backend import MandrillBackendMockAPITestCase
+
+
+class MandrillBackendDjrillFeatureTests(MandrillBackendMockAPITestCase):
+    """Test backend support for features leftover from Djrill"""
+
+    # Most of these features should be moved to esp_extra.
+    # The template and merge_ta
+
+    def test_djrill_message_options(self):
+        self.message.url_strip_qs = True
+        self.message.important = True
+        self.message.auto_text = True
+        self.message.auto_html = True
+        self.message.inline_css = True
+        self.message.preserve_recipients = True
+        self.message.view_content_link = False
+        self.message.tracking_domain = "click.example.com"
+        self.message.signing_domain = "example.com"
+        self.message.return_path_domain = "support.example.com"
+        self.message.subaccount = "marketing-dept"
+        self.message.async = True
+        self.message.ip_pool = "Bulk Pool"
+        self.message.send()
+        data = self.get_api_call_json()
+        self.assertEqual(data['message']['url_strip_qs'], True)
+        self.assertEqual(data['message']['important'], True)
+        self.assertEqual(data['message']['auto_text'], True)
+        self.assertEqual(data['message']['auto_html'], True)
+        self.assertEqual(data['message']['inline_css'], True)
+        self.assertEqual(data['message']['preserve_recipients'], True)
+        self.assertEqual(data['message']['view_content_link'], False)
+        self.assertEqual(data['message']['tracking_domain'], "click.example.com")
+        self.assertEqual(data['message']['signing_domain'], "example.com")
+        self.assertEqual(data['message']['return_path_domain'], "support.example.com")
+        self.assertEqual(data['message']['subaccount'], "marketing-dept")
+        self.assertEqual(data['async'], True)
+        self.assertEqual(data['ip_pool'], "Bulk Pool")
+
+    def test_google_analytics(self):
+        self.message.google_analytics_domains = ["example.com"]
+        self.message.google_analytics_campaign = "Email Receipts"
+        self.message.send()
+        data = self.get_api_call_json()
+        self.assertEqual(data['message']['google_analytics_domains'], ["example.com"])
+        self.assertEqual(data['message']['google_analytics_campaign'], "Email Receipts")
+
+    def test_recipient_metadata(self):
+        self.message.recipient_metadata = {
+            # Anymail expands simple python dicts into the more-verbose
+            # rcpt/values structures the Mandrill API uses
+            "customer@example.com": {'cust_id': "67890", 'order_id': "54321"},
+            "guest@example.com": {'cust_id': "94107", 'order_id': "43215"}
+        }
+        self.message.send()
+        data = self.get_api_call_json()
+        self.assertEqual(data['message']['recipient_metadata'],
+                         [{'rcpt': "customer@example.com",
+                           'values': {'cust_id': "67890", 'order_id': "54321"}},
+                          {'rcpt': "guest@example.com",
+                           'values': {'cust_id': "94107", 'order_id': "43215"}}
+                          ])
+
+    def test_no_subaccount_by_default(self):
+        mail.send_mail('Subject', 'Body', 'from@example.com', ['to@example.com'])
+        data = self.get_api_call_json()
+        self.assertFalse('subaccount' in data['message'])
+
+    @override_settings(ANYMAIL_MANDRILL_SEND_DEFAULTS={'subaccount': 'test_subaccount'})
+    def test_subaccount_setting(self):
+        mail.send_mail('Subject', 'Body', 'from@example.com', ['to@example.com'])
+        data = self.get_api_call_json()
+        self.assertEqual(data['message']['subaccount'], "test_subaccount")
+
+    @override_settings(ANYMAIL_MANDRILL_SEND_DEFAULTS={'subaccount': 'global_setting_subaccount'})
+    def test_subaccount_message_overrides_setting(self):
+        message = mail.EmailMessage('Subject', 'Body', 'from@example.com', ['to@example.com'])
+        message.subaccount = "individual_message_subaccount"  # should override global setting
+        message.send()
+        data = self.get_api_call_json()
+        self.assertEqual(data['message']['subaccount'], "individual_message_subaccount")
+
+    def test_default_omits_options(self):
+        """Make sure by default we don't send any Mandrill-specific options.
+
+        Options not specified by the caller should be omitted entirely from
+        the Mandrill API call (*not* sent as False or empty). This ensures
+        that your Mandrill account settings apply by default.
+        """
+        self.message.send()
+        self.assert_esp_called("/messages/send.json")
+        data = self.get_api_call_json()
+        self.assertFalse('from_name' in data['message'])
+        self.assertFalse('bcc_address' in data['message'])
+        self.assertFalse('important' in data['message'])
+        self.assertFalse('auto_text' in data['message'])
+        self.assertFalse('auto_html' in data['message'])
+        self.assertFalse('inline_css' in data['message'])
+        self.assertFalse('url_strip_qs' in data['message'])
+        self.assertFalse('preserve_recipients' in data['message'])
+        self.assertFalse('view_content_link' in data['message'])
+        self.assertFalse('tracking_domain' in data['message'])
+        self.assertFalse('signing_domain' in data['message'])
+        self.assertFalse('return_path_domain' in data['message'])
+        self.assertFalse('subaccount' in data['message'])
+        self.assertFalse('google_analytics_domains' in data['message'])
+        self.assertFalse('google_analytics_campaign' in data['message'])
+        self.assertFalse('merge_language' in data['message'])
+        self.assertFalse('global_merge_vars' in data['message'])
+        self.assertFalse('merge_vars' in data['message'])
+        self.assertFalse('recipient_metadata' in data['message'])
+        # Options at top level of api params (not in message dict):
+        self.assertFalse('async' in data)
+        self.assertFalse('ip_pool' in data)
+
+    def test_dates_not_serialized(self):
+        """Old versions of predecessor package Djrill accidentally serialized dates to ISO"""
+        self.message.metadata = {'SHIP_DATE': date(2015, 12, 2)}
+        with self.assertRaises(AnymailSerializationError):
+            self.message.send()
+
+
+@override_settings(ANYMAIL_SEND_DEFAULTS={
+    'from_name': 'Djrill Test',
+    'important': True,
+    'auto_text': True,
+    'auto_html': True,
+    'inline_css': True,
+    'url_strip_qs': True,
+    'preserve_recipients': True,
+    'view_content_link': True,
+    'subaccount': 'example-subaccount',
+    'tracking_domain': 'example.com',
+    'signing_domain': 'example.com',
+    'return_path_domain': 'example.com',
+    'google_analytics_domains': ['example.com/test'],
+    'google_analytics_campaign': ['UA-00000000-1'],
+    'merge_language': 'mailchimp',
+    'global_merge_vars': {'TEST': 'djrill'},
+    'async': True,
+    'ip_pool': 'Pool1',
+    'invalid': 'invalid',
+})
+class MandrillBackendDjrillSendDefaultsTests(MandrillBackendMockAPITestCase):
+    """Tests backend support for global SEND_DEFAULTS"""
+
+    def test_global_options(self):
+        """Test that any global settings get passed through
+        """
+        self.message.send()
+        data = self.get_api_call_json()
+        self.assertEqual(data['message']['from_name'], 'Djrill Test')
+        self.assertTrue(data['message']['important'])
+        self.assertTrue(data['message']['auto_text'])
+        self.assertTrue(data['message']['auto_html'])
+        self.assertTrue(data['message']['inline_css'])
+        self.assertTrue(data['message']['url_strip_qs'])
+        self.assertTrue(data['message']['preserve_recipients'])
+        self.assertTrue(data['message']['view_content_link'])
+        self.assertEqual(data['message']['subaccount'], 'example-subaccount')
+        self.assertEqual(data['message']['tracking_domain'], 'example.com')
+        self.assertEqual(data['message']['signing_domain'], 'example.com')
+        self.assertEqual(data['message']['return_path_domain'], 'example.com')
+        self.assertEqual(data['message']['google_analytics_domains'], ['example.com/test'])
+        self.assertEqual(data['message']['google_analytics_campaign'], ['UA-00000000-1'])
+        self.assertEqual(data['message']['merge_language'], 'mailchimp')
+        self.assertEqual(data['message']['global_merge_vars'],
+                         [{'name': 'TEST', 'content': 'djrill'}])
+        self.assertFalse('merge_vars' in data['message'])
+        self.assertFalse('recipient_metadata' in data['message'])
+        # Options at top level of api params (not in message dict):
+        self.assertTrue(data['async'])
+        self.assertEqual(data['ip_pool'], 'Pool1')
+        # Option that shouldn't be added
+        self.assertFalse('invalid' in data['message'])
+
+    def test_global_options_override(self):
+        """Test that manually settings options overrides global settings
+        """
+        self.message.from_name = "override"
+        self.message.important = False
+        self.message.auto_text = False
+        self.message.auto_html = False
+        self.message.inline_css = False
+        self.message.url_strip_qs = False
+        self.message.preserve_recipients = False
+        self.message.view_content_link = False
+        self.message.subaccount = "override"
+        self.message.tracking_domain = "override.example.com"
+        self.message.signing_domain = "override.example.com"
+        self.message.return_path_domain = "override.example.com"
+        self.message.google_analytics_domains = ['override.example.com']
+        self.message.google_analytics_campaign = ['UA-99999999-1']
+        self.message.merge_language = 'handlebars'
+        self.message.async = False
+        self.message.ip_pool = "Bulk Pool"
+        self.message.send()
+        data = self.get_api_call_json()
+        self.assertEqual(data['message']['from_name'], 'override')
+        self.assertFalse(data['message']['important'])
+        self.assertFalse(data['message']['auto_text'])
+        self.assertFalse(data['message']['auto_html'])
+        self.assertFalse(data['message']['inline_css'])
+        self.assertFalse(data['message']['url_strip_qs'])
+        self.assertFalse(data['message']['preserve_recipients'])
+        self.assertFalse(data['message']['view_content_link'])
+        self.assertEqual(data['message']['subaccount'], 'override')
+        self.assertEqual(data['message']['tracking_domain'], 'override.example.com')
+        self.assertEqual(data['message']['signing_domain'], 'override.example.com')
+        self.assertEqual(data['message']['return_path_domain'], 'override.example.com')
+        self.assertEqual(data['message']['google_analytics_domains'], ['override.example.com'])
+        self.assertEqual(data['message']['google_analytics_campaign'], ['UA-99999999-1'])
+        self.assertEqual(data['message']['merge_language'], 'handlebars')
+        self.assertEqual(data['message']['global_merge_vars'], [{'name': 'TEST', 'content': 'djrill'}])
+        # Options at top level of api params (not in message dict):
+        self.assertFalse(data['async'])
+        self.assertEqual(data['ip_pool'], 'Bulk Pool')
+
+    def test_global_merge(self):
+        # Test that global settings merge in
+        self.message.global_merge_vars = {'GREETING': "Hello"}
+        self.message.send()
+        data = self.get_api_call_json()
+        self.assertEqual(data['message']['global_merge_vars'],
+                         [{'name': "GREETING", 'content': "Hello"},
+                          {'name': 'TEST', 'content': 'djrill'}])
+
+    def test_global_merge_overwrite(self):
+        # Test that global merge settings are overwritten
+        self.message.global_merge_vars = {'TEST': "Hello"}
+        self.message.send()
+        data = self.get_api_call_json()
+        self.assertEqual(data['message']['global_merge_vars'],
+                         [{'name': 'TEST', 'content': 'Hello'}])
+
+
+class MandrillBackendDjrillTemplateTests(MandrillBackendMockAPITestCase):
+    """Test backend support for ESP templating features"""
+
+    # Holdovers from Djrill, until we design Anymail's normalized esp-template support
+
+    def test_merge_data(self):
+        # Anymail expands simple python dicts into the more-verbose name/content
+        # structures the Mandrill API uses
+        self.message.merge_language = "mailchimp"
+        self.message.global_merge_vars = {'GREETING': "Hello",
+                                          'ACCOUNT_TYPE': "Basic"}
+        self.message.merge_vars = {
+            "customer@example.com": {'GREETING': "Dear Customer",
+                                     'ACCOUNT_TYPE': "Premium"},
+            "guest@example.com": {'GREETING': "Dear Guest"},
+        }
+        self.message.send()
+        data = self.get_api_call_json()
+        self.assertEqual(data['message']['merge_language'], "mailchimp")
+        self.assertEqual(data['message']['global_merge_vars'],
+                         [{'name': 'ACCOUNT_TYPE', 'content': "Basic"},
+                          {'name': "GREETING", 'content': "Hello"}])
+        self.assertEqual(data['message']['merge_vars'],
+                         [{'rcpt': "customer@example.com",
+                           'vars': [{'name': 'ACCOUNT_TYPE', 'content': "Premium"},
+                                    {'name': "GREETING", 'content': "Dear Customer"}]},
+                          {'rcpt': "guest@example.com",
+                           'vars': [{'name': "GREETING", 'content': "Dear Guest"}]}
+                          ])
+
+    def test_send_template(self):
+        self.message.template_name = "PERSONALIZED_SPECIALS"
+        self.message.template_content = {
+            'HEADLINE': "<h1>Specials Just For *|FNAME|*</h1>",
+            'OFFER_BLOCK': "<p><em>Half off</em> all fruit</p>"
+        }
+        self.message.send()
+        self.assert_esp_called("/messages/send-template.json")
+        data = self.get_api_call_json()
+        self.assertEqual(data['template_name'], "PERSONALIZED_SPECIALS")
+        # Anymail expands simple python dicts into the more-verbose name/content
+        # structures the Mandrill API uses
+        self.assertEqual(data['template_content'],
+                         [{'name': "HEADLINE",
+                           'content': "<h1>Specials Just For *|FNAME|*</h1>"},
+                          {'name': "OFFER_BLOCK",
+                           'content': "<p><em>Half off</em> all fruit</p>"}])
+
+    def test_send_template_without_from_field(self):
+        self.message.template_name = "PERSONALIZED_SPECIALS"
+        self.message.use_template_from = True
+        self.message.send()
+        self.assert_esp_called("/messages/send-template.json")
+        data = self.get_api_call_json()
+        self.assertEqual(data['template_name'], "PERSONALIZED_SPECIALS")
+        self.assertFalse('from_email' in data['message'])
+        self.assertFalse('from_name' in data['message'])
+
+    def test_send_template_without_from_field_api_failure(self):
+        self.set_mock_response(status_code=400)
+        self.message.template_name = "PERSONALIZED_SPECIALS"
+        self.message.use_template_from = True
+        with self.assertRaises(AnymailAPIError):
+            self.message.send()
+
+    def test_send_template_without_subject_field(self):
+        self.message.template_name = "PERSONALIZED_SPECIALS"
+        self.message.use_template_subject = True
+        self.message.send()
+        self.assert_esp_called("/messages/send-template.json")
+        data = self.get_api_call_json()
+        self.assertEqual(data['template_name'], "PERSONALIZED_SPECIALS")
+        self.assertFalse('subject' in data['message'])
+
+    def test_no_template_content(self):
+        # Just a template, without any template_content to be merged
+        self.message.template_name = "WELCOME_MESSAGE"
+        self.message.send()
+        self.assert_esp_called("/messages/send-template.json")
+        data = self.get_api_call_json()
+        self.assertEqual(data['template_name'], "WELCOME_MESSAGE")
+        self.assertEqual(data['template_content'], [])  # Mandrill requires this field
+
+    def test_non_template_send(self):
+        # Make sure the non-template case still uses /messages/send.json
+        self.message.send()
+        self.assert_esp_called("/messages/send.json")
+        data = self.get_api_call_json()
+        self.assertFalse('template_name' in data)
+        self.assertFalse('template_content' in data)
+        self.assertFalse('async' in data)
diff --git a/anymail/tests/test_mandrill_integration.py b/anymail/tests/test_mandrill_integration.py
index 00b4a03..8795ce6 100644
--- a/anymail/tests/test_mandrill_integration.py
+++ b/anymail/tests/test_mandrill_integration.py
@@ -4,20 +4,22 @@ import os
 import unittest
 
 from django.core import mail
-from django.test import TestCase
+from django.test import SimpleTestCase
 from django.test.utils import override_settings
 
 from anymail.exceptions import AnymailAPIError, AnymailRecipientsRefused
+from anymail.message import AnymailMessage
 
+from .utils import AnymailTestMixin, sample_image_path
 
 MANDRILL_TEST_API_KEY = os.getenv('MANDRILL_TEST_API_KEY')
 
 
 @unittest.skipUnless(MANDRILL_TEST_API_KEY,
-            "Set MANDRILL_TEST_API_KEY environment variable to run integration tests")
+                     "Set MANDRILL_TEST_API_KEY environment variable to run integration tests")
 @override_settings(MANDRILL_API_KEY=MANDRILL_TEST_API_KEY,
                    EMAIL_BACKEND="anymail.backends.mandrill.MandrillBackend")
-class DjrillIntegrationTests(TestCase):
+class MandrillBackendIntegrationTests(SimpleTestCase, AnymailTestMixin):
     """Mandrill API integration tests
 
     These tests run against the **live** Mandrill API, using the
@@ -30,11 +32,12 @@ class DjrillIntegrationTests(TestCase):
     """
 
     def setUp(self):
-        self.message = mail.EmailMultiAlternatives(
-            'Subject', 'Text content', 'from@example.com', ['to@example.com'])
+        super(MandrillBackendIntegrationTests, self).setUp()
+        self.message = mail.EmailMultiAlternatives('Anymail Mandrill integration test', 'Text content',
+                                                   'from@example.com', ['to@example.com'])
         self.message.attach_alternative('<p>HTML content</p>', "text/html")
 
-    def test_send_mail(self):
+    def test_simple_send(self):
         # Example of getting the Mandrill send status and _id from the message
         sent_count = self.message.send()
         self.assertEqual(sent_count, 1)
@@ -50,16 +53,41 @@ class DjrillIntegrationTests(TestCase):
         self.assertEqual(anymail_status.status, {sent_status})  # set of all recipient statuses
         self.assertEqual(anymail_status.message_id, message_id)  # because only a single recipient (else would be a set)
 
+    def test_all_options(self):
+        message = AnymailMessage(
+            subject="Anymail all-options integration test",
+            body="This is the text body",
+            from_email="Test From <from@example.com>",
+            to=["to1@example.com", "Recipient 2 <to2@example.com>"],
+            cc=["cc1@example.com", "Copy 2 <cc2@example.com>"],
+            bcc=["bcc1@example.com", "Blind Copy 2 <bcc2@example.com>"],
+            reply_to=["reply1@example.com", "Reply 2 <reply2@example.com>"],
+            headers={"X-Anymail-Test": "value"},
+
+            # no metadata, send_at, track_clicks support
+            tags=["tag 1"],  # max one tag
+            track_opens=True,
+        )
+        message.attach("attachment1.txt", "Here is some\ntext for you", "text/plain")
+        message.attach("attachment2.csv", "ID,Name\n1,Amy Lina", "text/csv")
+        cid = message.attach_inline_image_file(sample_image_path())
+        message.attach_alternative(
+            "<p><b>HTML:</b> with <a href='http://example.com'>link</a>"
+            "and image: <img src='cid:%s'></div>" % cid,
+            "text/html")
+
+        message.send()
+        self.assertTrue(message.anymail_status.status.issubset({'queued', 'sent'}))
+
     def test_invalid_from(self):
         # Example of trying to send from an invalid address
         # Mandrill returns a 500 response (which raises a MandrillAPIError)
         self.message.from_email = 'webmaster@localhost'  # Django default DEFAULT_FROM_EMAIL
-        try:
+        with self.assertRaises(AnymailAPIError) as cm:
             self.message.send()
-            self.fail("This line will not be reached, because send() raised an exception")
-        except AnymailAPIError as err:
-            self.assertEqual(err.status_code, 500)
-            self.assertIn("email address is invalid", str(err))
+        err = cm.exception
+        self.assertEqual(err.status_code, 500)
+        self.assertIn("email address is invalid", str(err))
 
     def test_invalid_to(self):
         # Example of detecting when a recipient is not a valid email address
@@ -102,9 +130,9 @@ class DjrillIntegrationTests(TestCase):
     @override_settings(MANDRILL_API_KEY="Hey, that's not an API key!")
     def test_invalid_api_key(self):
         # Example of trying to send with an invalid MANDRILL_API_KEY
-        try:
+        with self.assertRaises(AnymailAPIError) as cm:
             self.message.send()
-            self.fail("This line will not be reached, because send() raised an exception")
-        except AnymailAPIError as err:
-            self.assertEqual(err.status_code, 500)
-            self.assertIn("Invalid API key", str(err))
+        err = cm.exception
+        self.assertEqual(err.status_code, 500)
+        # Make sure the exception message includes Mandrill's response:
+        self.assertIn("Invalid API key", str(err))
diff --git a/anymail/tests/test_mandrill_send.py b/anymail/tests/test_mandrill_send.py
deleted file mode 100644
index e8f469d..0000000
--- a/anymail/tests/test_mandrill_send.py
+++ /dev/null
@@ -1,765 +0,0 @@
-# -*- coding: utf-8 -*-
-
-from __future__ import unicode_literals
-
-import json
-import os
-import six
-import unittest
-from base64 import b64decode
-from datetime import date, datetime
-from decimal import Decimal
-from email.mime.base import MIMEBase
-from email.mime.image import MIMEImage
-
-from django.core import mail
-from django.core.exceptions import ImproperlyConfigured
-from django.test import TestCase
-from django.test.utils import override_settings
-from django.utils.timezone import get_fixed_timezone, override as override_current_timezone
-
-from anymail.exceptions import (AnymailAPIError, AnymailRecipientsRefused,
-                                AnymailSerializationError, AnymailUnsupportedFeature)
-from anymail.message import attach_inline_image
-
-from .mock_backend import DjrillBackendMockAPITestCase
-
-
-def decode_att(att):
-    """Returns the original data from base64-encoded attachment content"""
-    return b64decode(att.encode('ascii'))
-
-
-class DjrillBackendTests(DjrillBackendMockAPITestCase):
-    """Test Djrill backend support for Django mail wrappers"""
-
-    sample_image_filename = "sample_image.png"
-
-    def sample_image_pathname(self):
-        """Returns path to an actual image file in the tests directory"""
-        test_dir = os.path.dirname(os.path.abspath(__file__))
-        path = os.path.join(test_dir, self.sample_image_filename)
-        return path
-
-    def sample_image_content(self):
-        """Returns contents of an actual image file from the tests directory"""
-        filename = self.sample_image_pathname()
-        with open(filename, "rb") as f:
-            return f.read()
-
-    def test_send_mail(self):
-        mail.send_mail('Subject here', 'Here is the message.',
-            'from@example.com', ['to@example.com'], fail_silently=False)
-        self.assert_mandrill_called("/messages/send.json")
-        data = self.get_api_call_data()
-        self.assertEqual(data['message']['subject'], "Subject here")
-        self.assertEqual(data['message']['text'], "Here is the message.")
-        self.assertFalse('from_name' in data['message'])
-        self.assertEqual(data['message']['from_email'], "from@example.com")
-        self.assertEqual(len(data['message']['to']), 1)
-        self.assertEqual(data['message']['to'][0]['email'], "to@example.com")
-
-    def test_name_addr(self):
-        """Make sure RFC2822 name-addr format (with display-name) is allowed
-
-        (Test both sender and recipient addresses)
-        """
-        msg = mail.EmailMessage('Subject', 'Message',
-            'From Name <from@example.com>',
-            ['Recipient #1 <to1@example.com>', 'to2@example.com'],
-            cc=['Carbon Copy <cc1@example.com>', 'cc2@example.com'],
-            bcc=['Blind Copy <bcc1@example.com>', 'bcc2@example.com'])
-        msg.send()
-        data = self.get_api_call_data()
-        self.assertEqual(data['message']['from_name'], "From Name")
-        self.assertEqual(data['message']['from_email'], "from@example.com")
-        self.assertEqual(len(data['message']['to']), 6)
-        self.assertEqual(data['message']['to'][0]['name'], "Recipient #1")
-        self.assertEqual(data['message']['to'][0]['email'], "to1@example.com")
-        self.assertEqual(data['message']['to'][1]['name'], "")
-        self.assertEqual(data['message']['to'][1]['email'], "to2@example.com")
-        self.assertEqual(data['message']['to'][2]['name'], "Carbon Copy")
-        self.assertEqual(data['message']['to'][2]['email'], "cc1@example.com")
-        self.assertEqual(data['message']['to'][3]['name'], "")
-        self.assertEqual(data['message']['to'][3]['email'], "cc2@example.com")
-        self.assertEqual(data['message']['to'][4]['name'], "Blind Copy")
-        self.assertEqual(data['message']['to'][4]['email'], "bcc1@example.com")
-        self.assertEqual(data['message']['to'][5]['name'], "")
-        self.assertEqual(data['message']['to'][5]['email'], "bcc2@example.com")
-
-    def test_email_message(self):
-        email = mail.EmailMessage('Subject', 'Body goes here',
-            'from@example.com',
-            ['to1@example.com', 'Also To <to2@example.com>'],
-            bcc=['bcc1@example.com', 'Also BCC <bcc2@example.com>'],
-            cc=['cc1@example.com', 'Also CC <cc2@example.com>'],
-            headers={'Reply-To': 'another@example.com',
-                     'X-MyHeader': 'my value',
-                     'Message-ID': 'mycustommsgid@example.com'})
-        email.send()
-        self.assert_mandrill_called("/messages/send.json")
-        data = self.get_api_call_data()
-        self.assertEqual(data['message']['subject'], "Subject")
-        self.assertEqual(data['message']['text'], "Body goes here")
-        self.assertEqual(data['message']['from_email'], "from@example.com")
-        self.assertEqual(data['message']['headers'],
-                         {'Reply-To': 'another@example.com',
-                          'X-MyHeader': 'my value',
-                          'Message-ID': 'mycustommsgid@example.com'})
-        # Verify recipients correctly identified as "to", "cc", or "bcc"
-        self.assertEqual(len(data['message']['to']), 6)
-        self.assertEqual(data['message']['to'][0]['email'], "to1@example.com")
-        self.assertEqual(data['message']['to'][0]['type'], "to")
-        self.assertEqual(data['message']['to'][1]['email'], "to2@example.com")
-        self.assertEqual(data['message']['to'][1]['type'], "to")
-        self.assertEqual(data['message']['to'][2]['email'], "cc1@example.com")
-        self.assertEqual(data['message']['to'][2]['type'], "cc")
-        self.assertEqual(data['message']['to'][3]['email'], "cc2@example.com")
-        self.assertEqual(data['message']['to'][3]['type'], "cc")
-        self.assertEqual(data['message']['to'][4]['email'], "bcc1@example.com")
-        self.assertEqual(data['message']['to'][4]['type'], "bcc")
-        self.assertEqual(data['message']['to'][5]['email'], "bcc2@example.com")
-        self.assertEqual(data['message']['to'][5]['type'], "bcc")
-        # Don't use Mandrill's bcc_address "logging" feature for bcc's:
-        self.assertNotIn('bcc_address', data['message'])
-
-    def test_html_message(self):
-        text_content = 'This is an important message.'
-        html_content = '<p>This is an <strong>important</strong> message.</p>'
-        email = mail.EmailMultiAlternatives('Subject', text_content,
-            'from@example.com', ['to@example.com'])
-        email.attach_alternative(html_content, "text/html")
-        email.send()
-        self.assert_mandrill_called("/messages/send.json")
-        data = self.get_api_call_data()
-        self.assertEqual(data['message']['text'], text_content)
-        self.assertEqual(data['message']['html'], html_content)
-        # Don't accidentally send the html part as an attachment:
-        self.assertFalse('attachments' in data['message'])
-
-    def test_html_only_message(self):
-        html_content = '<p>This is an <strong>important</strong> message.</p>'
-        email = mail.EmailMessage('Subject', html_content,
-            'from@example.com', ['to@example.com'])
-        email.content_subtype = "html"  # Main content is now text/html
-        email.send()
-        self.assert_mandrill_called("/messages/send.json")
-        data = self.get_api_call_data()
-        self.assertNotIn('text', data['message'])
-        self.assertEqual(data['message']['html'], html_content)
-
-    def test_reply_to(self):
-        # reply_to is new in Django 1.8 -- before that, you can simply include it in headers
-        try:
-            # noinspection PyArgumentList
-            email = mail.EmailMessage('Subject', 'Body goes here', 'from@example.com', ['to1@example.com'],
-                                      reply_to=['reply@example.com', 'Other <reply2@example.com>'],
-                                      headers={'X-Other': 'Keep'})
-        except TypeError:
-            # Pre-Django 1.8
-            raise unittest.SkipTest("Django version doesn't support EmailMessage(reply_to)")
-        email.send()
-        self.assert_mandrill_called("/messages/send.json")
-        data = self.get_api_call_data()
-        self.assertEqual(data['message']['headers']['Reply-To'],
-                         'reply@example.com, Other <reply2@example.com>')
-        self.assertEqual(data['message']['headers']['X-Other'], 'Keep')  # don't lose other headers
-
-    def test_attachments(self):
-        email = mail.EmailMessage('Subject', 'Body goes here', 'from@example.com', ['to1@example.com'])
-
-        text_content = "* Item one\n* Item two\n* Item three"
-        email.attach(filename="test.txt", content=text_content, mimetype="text/plain")
-
-        # Should guess mimetype if not provided...
-        png_content = b"PNG\xb4 pretend this is the contents of a png file"
-        email.attach(filename="test.png", content=png_content)
-
-        # Should work with a MIMEBase object (also tests no filename)...
-        pdf_content = b"PDF\xb4 pretend this is valid pdf data"
-        mimeattachment = MIMEBase('application', 'pdf')
-        mimeattachment.set_payload(pdf_content)
-        email.attach(mimeattachment)
-
-        # Attachment type that wasn't supported in early Mandrill releases:
-        ppt_content = b"PPT\xb4 pretend this is a valid ppt file"
-        email.attach(filename="presentation.ppt", content=ppt_content,
-                     mimetype="application/vnd.ms-powerpoint")
-
-        email.send()
-        data = self.get_api_call_data()
-        attachments = data['message']['attachments']
-        self.assertEqual(len(attachments), 4)
-        self.assertEqual(attachments[0]["type"], "text/plain")
-        self.assertEqual(attachments[0]["name"], "test.txt")
-        self.assertEqual(decode_att(attachments[0]["content"]).decode('ascii'), text_content)
-        self.assertEqual(attachments[1]["type"], "image/png")  # inferred from filename
-        self.assertEqual(attachments[1]["name"], "test.png")
-        self.assertEqual(decode_att(attachments[1]["content"]), png_content)
-        self.assertEqual(attachments[2]["type"], "application/pdf")
-        self.assertEqual(attachments[2]["name"], "")  # none
-        self.assertEqual(decode_att(attachments[2]["content"]), pdf_content)
-        self.assertEqual(attachments[3]["type"], "application/vnd.ms-powerpoint")
-        self.assertEqual(attachments[3]["name"], "presentation.ppt")
-        self.assertEqual(decode_att(attachments[3]["content"]), ppt_content)
-        # Make sure the image attachment is not treated as embedded:
-        self.assertFalse('images' in data['message'])
-
-    def test_unicode_attachment_correctly_decoded(self):
-        msg = mail.EmailMessage(
-            subject='Subject',
-            body='Body goes here',
-            from_email='from@example.com',
-            to=['to1@example.com'],
-        )
-        # Slight modification from the Django unicode docs:
-        # http://django.readthedocs.org/en/latest/ref/unicode.html#email
-        msg.attach("Une pièce jointe.html", '<p>\u2019</p>', mimetype='text/html')
-
-        msg.send()
-        data = self.get_api_call_data()
-
-        attachments = data['message']['attachments']
-        self.assertEqual(len(attachments), 1)
-
-    def test_embedded_images(self):
-        text_content = 'This has an inline image.'
-        email = mail.EmailMultiAlternatives('Subject', text_content, 'from@example.com', ['to@example.com'])
-
-        image_data = self.sample_image_content()  # Read from a png file
-        cid = attach_inline_image(email, image_data)
-
-        html_content = '<p>This has an <img src="cid:%s" alt="inline" /> image.</p>' % cid
-        email.attach_alternative(html_content, "text/html")
-
-        email.send()
-        data = self.get_api_call_data()
-        self.assertEqual(data['message']['text'], text_content)
-        self.assertEqual(data['message']['html'], html_content)
-        self.assertEqual(len(data['message']['images']), 1)
-        self.assertEqual(data['message']['images'][0]["type"], "image/png")
-        self.assertEqual(data['message']['images'][0]["name"], cid)
-        self.assertEqual(decode_att(data['message']['images'][0]["content"]), image_data)
-        # Make sure neither the html nor the inline image is treated as an attachment:
-        self.assertFalse('attachments' in data['message'])
-
-    def test_attached_images(self):
-        image_data = self.sample_image_content()
-
-        email = mail.EmailMultiAlternatives('Subject', 'Message', 'from@example.com', ['to@example.com'])
-        email.attach_file(self.sample_image_pathname())  # option 1: attach as a file
-
-        image = MIMEImage(image_data)  # option 2: construct the MIMEImage and attach it directly
-        email.attach(image)
-
-        email.send()
-        data = self.get_api_call_data()
-        attachments = data['message']['attachments']
-        self.assertEqual(len(attachments), 2)
-        self.assertEqual(attachments[0]["type"], "image/png")
-        self.assertEqual(attachments[0]["name"], self.sample_image_filename)
-        self.assertEqual(decode_att(attachments[0]["content"]), image_data)
-        self.assertEqual(attachments[1]["type"], "image/png")
-        self.assertEqual(attachments[1]["name"], "")  # unknown -- not attached as file
-        self.assertEqual(decode_att(attachments[1]["content"]), image_data)
-        # Make sure the image attachments are not treated as embedded:
-        self.assertFalse('images' in data['message'])
-
-    def test_alternative_errors(self):
-        # Multiple alternatives not allowed
-        email = mail.EmailMultiAlternatives('Subject', 'Body',
-            'from@example.com', ['to@example.com'])
-        email.attach_alternative("<p>First html is OK</p>", "text/html")
-        email.attach_alternative("<p>But not second html</p>", "text/html")
-        with self.assertRaises(AnymailUnsupportedFeature):
-            email.send()
-
-        # Only html alternatives allowed
-        email = mail.EmailMultiAlternatives('Subject', 'Body',
-            'from@example.com', ['to@example.com'])
-        email.attach_alternative("{'not': 'allowed'}", "application/json")
-        with self.assertRaises(AnymailUnsupportedFeature):
-            email.send()
-
-        # Make sure fail_silently is respected
-        email = mail.EmailMultiAlternatives('Subject', 'Body',
-            'from@example.com', ['to@example.com'])
-        email.attach_alternative("{'not': 'allowed'}", "application/json")
-        sent = email.send(fail_silently=True)
-        self.assertFalse(self.mock_post.called,
-            msg="Mandrill API should not be called when send fails silently")
-        self.assertEqual(sent, 0)
-
-    def test_mandrill_api_failure(self):
-        self.mock_post.return_value = self.MockResponse(status_code=400)
-        with self.assertRaises(AnymailAPIError):
-            sent = mail.send_mail('Subject', 'Body', 'from@example.com',
-                ['to@example.com'])
-            self.assertEqual(sent, 0)
-
-        # Make sure fail_silently is respected
-        self.mock_post.return_value = self.MockResponse(status_code=400)
-        sent = mail.send_mail('Subject', 'Body', 'from@example.com',
-            ['to@example.com'], fail_silently=True)
-        self.assertEqual(sent, 0)
-
-    def test_api_error_includes_details(self):
-        """MandrillAPIError should include Mandrill's error message"""
-        msg = mail.EmailMessage('Subject', 'Body', 'from@example.com', ['to@example.com'])
-
-        # JSON error response:
-        error_response = b"""{
-                                 "status": "error",
-                                 "code": 12,
-                                 "name": "Error_Name",
-                                 "message": "Helpful explanation from Mandrill"
-                             }"""
-        self.mock_post.return_value = self.MockResponse(status_code=400, raw=error_response)
-        with self.assertRaisesMessage(AnymailAPIError, "Helpful explanation from Mandrill"):
-            msg.send()
-
-        # Non-JSON error response:
-        self.mock_post.return_value = self.MockResponse(status_code=500, raw=b"Invalid API key")
-        with self.assertRaisesMessage(AnymailAPIError, "Invalid API key"):
-            msg.send()
-
-        # No content in the error response:
-        self.mock_post.return_value = self.MockResponse(status_code=502, raw=None)
-        with self.assertRaises(AnymailAPIError):
-            msg.send()
-
-
-class DjrillMandrillFeatureTests(DjrillBackendMockAPITestCase):
-    """Test Djrill backend support for Mandrill-specific features"""
-
-    def setUp(self):
-        super(DjrillMandrillFeatureTests, self).setUp()
-        self.message = mail.EmailMessage('Subject', 'Text Body',
-            'from@example.com', ['to@example.com'])
-
-    def test_tracking(self):
-        # First make sure we're not setting the API param if the track_click
-        # attr isn't there. (The Mandrill account option of True for html,
-        # False for plaintext can't be communicated through the API, other than
-        # by omitting the track_clicks API param to use your account default.)
-        self.message.send()
-        data = self.get_api_call_data()
-        self.assertFalse('track_clicks' in data['message'])
-        # Now re-send with the params set
-        self.message.track_opens = True
-        self.message.track_clicks = True
-        self.message.url_strip_qs = True
-        self.message.send()
-        data = self.get_api_call_data()
-        self.assertEqual(data['message']['track_opens'], True)
-        self.assertEqual(data['message']['track_clicks'], True)
-        self.assertEqual(data['message']['url_strip_qs'], True)
-
-    def test_message_options(self):
-        self.message.important = True
-        self.message.auto_text = True
-        self.message.auto_html = True
-        self.message.inline_css = True
-        self.message.preserve_recipients = True
-        self.message.view_content_link = False
-        self.message.tracking_domain = "click.example.com"
-        self.message.signing_domain = "example.com"
-        self.message.return_path_domain = "support.example.com"
-        self.message.subaccount = "marketing-dept"
-        self.message.async = True
-        self.message.ip_pool = "Bulk Pool"
-        self.message.send()
-        data = self.get_api_call_data()
-        self.assertEqual(data['message']['important'], True)
-        self.assertEqual(data['message']['auto_text'], True)
-        self.assertEqual(data['message']['auto_html'], True)
-        self.assertEqual(data['message']['inline_css'], True)
-        self.assertEqual(data['message']['preserve_recipients'], True)
-        self.assertEqual(data['message']['view_content_link'], False)
-        self.assertEqual(data['message']['tracking_domain'], "click.example.com")
-        self.assertEqual(data['message']['signing_domain'], "example.com")
-        self.assertEqual(data['message']['return_path_domain'], "support.example.com")
-        self.assertEqual(data['message']['subaccount'], "marketing-dept")
-        self.assertEqual(data['async'], True)
-        self.assertEqual(data['ip_pool'], "Bulk Pool")
-
-    def test_merge(self):
-        # Djrill expands simple python dicts into the more-verbose name/content
-        # structures the Mandrill API uses
-        self.message.merge_language = "mailchimp"
-        self.message.global_merge_vars = { 'GREETING': "Hello",
-                                           'ACCOUNT_TYPE': "Basic" }
-        self.message.merge_vars = {
-            "customer@example.com": { 'GREETING': "Dear Customer",
-                                      'ACCOUNT_TYPE': "Premium" },
-            "guest@example.com": { 'GREETING': "Dear Guest" },
-            }
-        self.message.send()
-        data = self.get_api_call_data()
-        self.assertEqual(data['message']['merge_language'], "mailchimp")
-        self.assertEqual(data['message']['global_merge_vars'],
-            [ {'name': 'ACCOUNT_TYPE', 'content': "Basic"},
-              {'name': "GREETING", 'content': "Hello"} ])
-        self.assertEqual(data['message']['merge_vars'],
-            [ { 'rcpt': "customer@example.com",
-                'vars': [{ 'name': 'ACCOUNT_TYPE', 'content': "Premium" },
-                         { 'name': "GREETING", 'content': "Dear Customer"}] },
-              { 'rcpt': "guest@example.com",
-                'vars': [{ 'name': "GREETING", 'content': "Dear Guest"}] }
-            ])
-
-    def test_tags(self):
-        self.message.tags = ["receipt", "repeat-user"]
-        self.message.send()
-        data = self.get_api_call_data()
-        self.assertEqual(data['message']['tags'], ["receipt", "repeat-user"])
-
-    def test_google_analytics(self):
-        self.message.google_analytics_domains = ["example.com"]
-        self.message.google_analytics_campaign = "Email Receipts"
-        self.message.send()
-        data = self.get_api_call_data()
-        self.assertEqual(data['message']['google_analytics_domains'],
-            ["example.com"])
-        self.assertEqual(data['message']['google_analytics_campaign'],
-            "Email Receipts")
-
-    def test_metadata(self):
-        self.message.metadata = { 'batch_num': "12345", 'type': "Receipts" }
-        self.message.recipient_metadata = {
-            # Djrill expands simple python dicts into the more-verbose
-            # rcpt/values structures the Mandrill API uses
-            "customer@example.com": { 'cust_id': "67890", 'order_id': "54321" },
-            "guest@example.com": { 'cust_id': "94107", 'order_id': "43215" }
-        }
-        self.message.send()
-        data = self.get_api_call_data()
-        self.assertEqual(data['message']['metadata'], { 'batch_num': "12345",
-                                                        'type': "Receipts" })
-        self.assertEqual(data['message']['recipient_metadata'],
-            [ { 'rcpt': "customer@example.com",
-                'values': { 'cust_id': "67890", 'order_id': "54321" } },
-              { 'rcpt': "guest@example.com",
-                'values': { 'cust_id': "94107", 'order_id': "43215" } }
-            ])
-
-    def test_send_at(self):
-        utc_plus_6 = get_fixed_timezone(6 * 60)
-        utc_minus_8 = get_fixed_timezone(-8 * 60)
-
-        with override_current_timezone(utc_plus_6):
-            # Timezone-naive datetime assumed to be Django current_timezone
-            self.message.send_at = datetime(2022, 10, 11, 12, 13, 14, 567)
-            self.message.send()
-            data = self.get_api_call_data()
-            self.assertEqual(data['send_at'], "2022-10-11 06:13:14")  # 12:13 UTC+6 == 06:13 UTC
-
-            # Timezone-aware datetime converted to UTC:
-            self.message.send_at = datetime(2016, 3, 4, 5, 6, 7, tzinfo=utc_minus_8)
-            self.message.send()
-            data = self.get_api_call_data()
-            self.assertEqual(data['send_at'], "2016-03-04 13:06:07")  # 05:06 UTC-8 == 13:06 UTC
-
-            # Date-only treated as midnight in current timezone
-            self.message.send_at = date(2022, 10, 22)
-            self.message.send()
-            data = self.get_api_call_data()
-            self.assertEqual(data['send_at'], "2022-10-21 18:00:00")  # 00:00 UTC+6 == 18:00-1d UTC
-
-            # POSIX timestamp
-            self.message.send_at = 1651820889  # 2022-05-06 07:08:09 UTC
-            self.message.send()
-            data = self.get_api_call_data()
-            self.assertEqual(data['send_at'], "2022-05-06 07:08:09")
-
-            # String passed unchanged (this is *not* portable between ESPs)
-            self.message.send_at = "2013-11-12 01:02:03"
-            self.message.send()
-            data = self.get_api_call_data()
-            self.assertEqual(data['send_at'], "2013-11-12 01:02:03")
-
-    def test_default_omits_options(self):
-        """Make sure by default we don't send any Mandrill-specific options.
-
-        Options not specified by the caller should be omitted entirely from
-        the Mandrill API call (*not* sent as False or empty). This ensures
-        that your Mandrill account settings apply by default.
-        """
-        self.message.send()
-        self.assert_mandrill_called("/messages/send.json")
-        data = self.get_api_call_data()
-        self.assertFalse('from_name' in data['message'])
-        self.assertFalse('bcc_address' in data['message'])
-        self.assertFalse('important' in data['message'])
-        self.assertFalse('track_opens' in data['message'])
-        self.assertFalse('track_clicks' in data['message'])
-        self.assertFalse('auto_text' in data['message'])
-        self.assertFalse('auto_html' in data['message'])
-        self.assertFalse('inline_css' in data['message'])
-        self.assertFalse('url_strip_qs' in data['message'])
-        self.assertFalse('tags' in data['message'])
-        self.assertFalse('preserve_recipients' in data['message'])
-        self.assertFalse('view_content_link' in data['message'])
-        self.assertFalse('tracking_domain' in data['message'])
-        self.assertFalse('signing_domain' in data['message'])
-        self.assertFalse('return_path_domain' in data['message'])
-        self.assertFalse('subaccount' in data['message'])
-        self.assertFalse('google_analytics_domains' in data['message'])
-        self.assertFalse('google_analytics_campaign' in data['message'])
-        self.assertFalse('metadata' in data['message'])
-        self.assertFalse('merge_language' in data['message'])
-        self.assertFalse('global_merge_vars' in data['message'])
-        self.assertFalse('merge_vars' in data['message'])
-        self.assertFalse('recipient_metadata' in data['message'])
-        self.assertFalse('images' in data['message'])
-        # Options at top level of api params (not in message dict):
-        self.assertFalse('send_at' in data)
-        self.assertFalse('async' in data)
-        self.assertFalse('ip_pool' in data)
-
-    # noinspection PyUnresolvedReferences
-    def test_send_attaches_anymail_status(self):
-        """ The anymail_status should be attached to the message when it is sent """
-        response = [{'email': 'to1@example.com', 'status': 'sent', '_id': 'abc123'}]
-        self.mock_post.return_value = self.MockResponse(raw=six.b(json.dumps(response)))
-        msg = mail.EmailMessage('Subject', 'Message', 'from@example.com', ['to1@example.com'],)
-        sent = msg.send()
-        self.assertEqual(sent, 1)
-        self.assertEqual(msg.anymail_status.status, {'sent'})
-        self.assertEqual(msg.anymail_status.message_id, 'abc123')
-        self.assertEqual(msg.anymail_status.recipients['to1@example.com'].status, 'sent')
-        self.assertEqual(msg.anymail_status.recipients['to1@example.com'].message_id, 'abc123')
-        self.assertEqual(msg.anymail_status.esp_response.json(), response)
-
-    # noinspection PyUnresolvedReferences
-    def test_send_failed_anymail_status(self):
-        """ If the send fails, anymail_status should contain initial values"""
-        self.mock_post.return_value = self.MockResponse(status_code=500)
-        msg = mail.EmailMessage('Subject', 'Message', 'from@example.com', ['to1@example.com'],)
-        sent = msg.send(fail_silently=True)
-        self.assertEqual(sent, 0)
-        self.assertIsNone(msg.anymail_status.status)
-        self.assertIsNone(msg.anymail_status.message_id)
-        self.assertEqual(msg.anymail_status.recipients, {})
-        self.assertIsNone(msg.anymail_status.esp_response)
-
-    # noinspection PyUnresolvedReferences
-    def test_send_unparsable_mandrill_response(self):
-        """If the send succeeds, but a non-JSON API response, should raise an API exception"""
-        self.mock_post.return_value = self.MockResponse(status_code=200, raw=b"this isn't json")
-        msg = mail.EmailMessage('Subject', 'Message', 'from@example.com', ['to1@example.com'],)
-        with self.assertRaises(AnymailAPIError):
-            msg.send()
-        self.assertIsNone(msg.anymail_status.status)
-        self.assertIsNone(msg.anymail_status.message_id)
-        self.assertEqual(msg.anymail_status.recipients, {})
-        self.assertEqual(msg.anymail_status.esp_response, self.mock_post.return_value)
-
-    def test_json_serialization_errors(self):
-        """Try to provide more information about non-json-serializable data"""
-        self.message.global_merge_vars = {'PRICE': Decimal('19.99')}
-        with self.assertRaises(AnymailSerializationError) as cm:
-            self.message.send()
-        err = cm.exception
-        self.assertTrue(isinstance(err, TypeError))  # Djrill 1.x re-raised TypeError from json.dumps
-        self.assertIn("Don't know how to send this data to Mandrill", str(err))  # our added context
-        self.assertIn("Decimal('19.99') is not JSON serializable", str(err))  # original message
-
-    def test_dates_not_serialized(self):
-        """Pre-2.0 Djrill accidentally serialized dates to ISO"""
-        self.message.global_merge_vars = {'SHIP_DATE': date(2015, 12, 2)}
-        with self.assertRaises(AnymailSerializationError):
-            self.message.send()
-
-
-class DjrillRecipientsRefusedTests(DjrillBackendMockAPITestCase):
-    """Djrill raises AnymailRecipientsRefused when *all* recipients are rejected or invalid"""
-
-    def test_recipients_refused(self):
-        msg = mail.EmailMessage('Subject', 'Body', 'from@example.com',
-                                ['invalid@localhost', 'reject@test.mandrillapp.com'])
-        self.mock_post.return_value = self.MockResponse(status_code=200, raw=b"""
-            [{ "email": "invalid@localhost", "status": "invalid" },
-             { "email": "reject@test.mandrillapp.com", "status": "rejected" }]""")
-        with self.assertRaises(AnymailRecipientsRefused):
-            msg.send()
-
-    def test_fail_silently(self):
-        self.mock_post.return_value = self.MockResponse(status_code=200, raw=b"""
-            [{ "email": "invalid@localhost", "status": "invalid" },
-             { "email": "reject@test.mandrillapp.com", "status": "rejected" }]""")
-        sent = mail.send_mail('Subject', 'Body', 'from@example.com',
-                              ['invalid@localhost', 'reject@test.mandrillapp.com'],
-                              fail_silently=True)
-        self.assertEqual(sent, 0)
-
-    def test_mixed_response(self):
-        """If *any* recipients are valid or queued, no exception is raised"""
-        msg = mail.EmailMessage('Subject', 'Body', 'from@example.com',
-                                ['invalid@localhost', 'valid@example.com',
-                                 'reject@test.mandrillapp.com', 'also.valid@example.com'])
-        self.mock_post.return_value = self.MockResponse(status_code=200, raw=b"""
-            [{ "email": "invalid@localhost", "status": "invalid" },
-             { "email": "valid@example.com", "status": "sent" },
-             { "email": "reject@test.mandrillapp.com", "status": "rejected" },
-             { "email": "also.valid@example.com", "status": "queued" }]""")
-        sent = msg.send()
-        self.assertEqual(sent, 1)  # one message sent, successfully, to 2 of 4 recipients
-
-    @override_settings(ANYMAIL_IGNORE_RECIPIENT_STATUS=True)
-    def test_settings_override(self):
-        """Setting restores Djrill 1.x behavior"""
-        self.mock_post.return_value = self.MockResponse(status_code=200, raw=b"""
-            [{ "email": "invalid@localhost", "status": "invalid" },
-             { "email": "reject@test.mandrillapp.com", "status": "rejected" }]""")
-        sent = mail.send_mail('Subject', 'Body', 'from@example.com',
-                              ['invalid@localhost', 'reject@test.mandrillapp.com'])
-        self.assertEqual(sent, 1)  # refused message is included in sent count
-
-
-@override_settings(ANYMAIL_SEND_DEFAULTS={
-    'from_name': 'Djrill Test',
-    'important': True,
-    'track_opens': True,
-    'track_clicks': True,
-    'auto_text': True,
-    'auto_html': True,
-    'inline_css': True,
-    'url_strip_qs': True,
-    'tags': ['djrill'],
-    'preserve_recipients': True,
-    'view_content_link': True,
-    'subaccount': 'example-subaccount',
-    'tracking_domain': 'example.com',
-    'signing_domain': 'example.com',
-    'return_path_domain': 'example.com',
-    'google_analytics_domains': ['example.com/test'],
-    'google_analytics_campaign': ['UA-00000000-1'],
-    'metadata': {'feature': 'global', 'plus': 'that'},
-    'merge_language': 'mailchimp',
-    'global_merge_vars': {'TEST': 'djrill'},
-    'async': True,
-    'ip_pool': 'Pool1',
-    'invalid': 'invalid',
-})
-class DjrillMandrillGlobalFeatureTests(DjrillBackendMockAPITestCase):
-    """Test Djrill backend support for global ovveride Mandrill-specific features"""
-
-    def setUp(self):
-        super(DjrillMandrillGlobalFeatureTests, self).setUp()
-        self.message = mail.EmailMessage('Subject', 'Text Body',
-                                         'from@example.com', ['to@example.com'])
-
-    def test_global_options(self):
-        """Test that any global settings get passed through
-        """
-        self.message.send()
-        self.assert_mandrill_called("/messages/send.json")
-        data = self.get_api_call_data()
-        self.assertEqual(data['message']['from_name'], 'Djrill Test')
-        self.assertTrue(data['message']['important'])
-        self.assertTrue(data['message']['track_opens'])
-        self.assertTrue(data['message']['track_clicks'])
-        self.assertTrue(data['message']['auto_text'])
-        self.assertTrue(data['message']['auto_html'])
-        self.assertTrue(data['message']['inline_css'])
-        self.assertTrue(data['message']['url_strip_qs'])
-        self.assertEqual(data['message']['tags'], ['djrill'])
-        self.assertTrue(data['message']['preserve_recipients'])
-        self.assertTrue(data['message']['view_content_link'])
-        self.assertEqual(data['message']['subaccount'], 'example-subaccount')
-        self.assertEqual(data['message']['tracking_domain'], 'example.com')
-        self.assertEqual(data['message']['signing_domain'], 'example.com')
-        self.assertEqual(data['message']['return_path_domain'], 'example.com')
-        self.assertEqual(data['message']['google_analytics_domains'], ['example.com/test'])
-        self.assertEqual(data['message']['google_analytics_campaign'], ['UA-00000000-1'])
-        self.assertEqual(data['message']['metadata'], {'feature': 'global', 'plus': 'that'})
-        self.assertEqual(data['message']['merge_language'], 'mailchimp')
-        self.assertEqual(data['message']['global_merge_vars'],
-                         [{'name': 'TEST', 'content': 'djrill'}])
-        self.assertFalse('merge_vars' in data['message'])
-        self.assertFalse('recipient_metadata' in data['message'])
-        # Options at top level of api params (not in message dict):
-        self.assertTrue(data['async'])
-        self.assertEqual(data['ip_pool'], 'Pool1')
-        # Option that shouldn't be added
-        self.assertFalse('invalid' in data['message'])
-
-    def test_global_options_override(self):
-        """Test that manually settings options overrides global settings
-        """
-        self.message.from_name = "override"
-        self.message.important = False
-        self.message.track_opens = False
-        self.message.track_clicks = False
-        self.message.auto_text = False
-        self.message.auto_html = False
-        self.message.inline_css = False
-        self.message.url_strip_qs = False
-        self.message.tags = ['override']
-        self.message.preserve_recipients = False
-        self.message.view_content_link = False
-        self.message.subaccount = "override"
-        self.message.tracking_domain = "override.example.com"
-        self.message.signing_domain = "override.example.com"
-        self.message.return_path_domain = "override.example.com"
-        self.message.google_analytics_domains = ['override.example.com']
-        self.message.google_analytics_campaign = ['UA-99999999-1']
-        self.message.metadata = {'feature': 'message', 'also': 'this'}
-        self.message.merge_language = 'handlebars'
-        self.message.async = False
-        self.message.ip_pool = "Bulk Pool"
-        self.message.send()
-        data = self.get_api_call_data()
-        self.assertEqual(data['message']['from_name'], 'override')
-        self.assertFalse(data['message']['important'])
-        self.assertFalse(data['message']['track_opens'])
-        self.assertFalse(data['message']['track_clicks'])
-        self.assertFalse(data['message']['auto_text'])
-        self.assertFalse(data['message']['auto_html'])
-        self.assertFalse(data['message']['inline_css'])
-        self.assertFalse(data['message']['url_strip_qs'])
-        self.assertEqual(data['message']['tags'], ['djrill', 'override'])  # tags are merged
-        self.assertFalse(data['message']['preserve_recipients'])
-        self.assertFalse(data['message']['view_content_link'])
-        self.assertEqual(data['message']['subaccount'], 'override')
-        self.assertEqual(data['message']['tracking_domain'], 'override.example.com')
-        self.assertEqual(data['message']['signing_domain'], 'override.example.com')
-        self.assertEqual(data['message']['return_path_domain'], 'override.example.com')
-        self.assertEqual(data['message']['google_analytics_domains'], ['override.example.com'])
-        self.assertEqual(data['message']['google_analytics_campaign'], ['UA-99999999-1'])
-        # metadata is merged:
-        self.assertEqual(data['message']['metadata'], {'feature': 'message', 'also': 'this', 'plus': 'that'})
-        self.assertEqual(data['message']['merge_language'], 'handlebars')
-        self.assertEqual(data['message']['global_merge_vars'],
-                         [{'name': 'TEST', 'content': 'djrill'}])
-        # Options at top level of api params (not in message dict):
-        self.assertFalse(data['async'])
-        self.assertEqual(data['ip_pool'], 'Bulk Pool')
-
-    def test_global_merge(self):
-        # Test that global settings merge in
-        self.message.global_merge_vars = {'GREETING': "Hello"}
-        self.message.send()
-        data = self.get_api_call_data()
-        self.assertEqual(data['message']['global_merge_vars'],
-                         [{'name': "GREETING", 'content': "Hello"},
-                          {'name': 'TEST', 'content': 'djrill'}])
-
-    def test_global_merge_overwrite(self):
-        # Test that global merge settings are overwritten
-        self.message.global_merge_vars = {'TEST': "Hello"}
-        self.message.send()
-        data = self.get_api_call_data()
-        self.assertEqual(data['message']['global_merge_vars'],
-                         [{'name': 'TEST', 'content': 'Hello'}])
-
-
-@override_settings(EMAIL_BACKEND="anymail.backends.mandrill.MandrillBackend")
-class DjrillImproperlyConfiguredTests(TestCase):
-    """Test Djrill backend without Djrill-specific settings in place"""
-
-    def test_missing_api_key(self):
-        with self.assertRaises(ImproperlyConfigured):
-            mail.send_mail('Subject', 'Message', 'from@example.com',
-                ['to@example.com'])
diff --git a/anymail/tests/test_mandrill_send_template.py b/anymail/tests/test_mandrill_send_template.py
deleted file mode 100644
index 325edb4..0000000
--- a/anymail/tests/test_mandrill_send_template.py
+++ /dev/null
@@ -1,84 +0,0 @@
-from django.core import mail
-
-from anymail.exceptions import AnymailAPIError
-
-from .mock_backend import DjrillBackendMockAPITestCase
-
-
-class DjrillMandrillSendTemplateTests(DjrillBackendMockAPITestCase):
-    """Test Djrill backend support for Mandrill send-template features"""
-
-    def test_send_template(self):
-        msg = mail.EmailMessage('Subject', 'Text Body',
-            'from@example.com', ['to@example.com'])
-        msg.template_name = "PERSONALIZED_SPECIALS"
-        msg.template_content = {
-            'HEADLINE': "<h1>Specials Just For *|FNAME|*</h1>",
-            'OFFER_BLOCK': "<p><em>Half off</em> all fruit</p>"
-        }
-        msg.send()
-        self.assert_mandrill_called("/messages/send-template.json")
-        data = self.get_api_call_data()
-        self.assertEqual(data['template_name'], "PERSONALIZED_SPECIALS")
-        # Djrill expands simple python dicts into the more-verbose name/content
-        # structures the Mandrill API uses
-        self.assertEqual(data['template_content'],
-            [ {'name': "HEADLINE",
-               'content': "<h1>Specials Just For *|FNAME|*</h1>"},
-              {'name': "OFFER_BLOCK",
-               'content': "<p><em>Half off</em> all fruit</p>"} ]
-        )
-
-    def test_send_template_without_from_field(self):
-        msg = mail.EmailMessage('Subject', 'Text Body',
-            'from@example.com', ['to@example.com'])
-        msg.template_name = "PERSONALIZED_SPECIALS"
-        msg.use_template_from = True
-        msg.send()
-        self.assert_mandrill_called("/messages/send-template.json")
-        data = self.get_api_call_data()
-        self.assertEqual(data['template_name'], "PERSONALIZED_SPECIALS")
-        self.assertFalse('from_email' in data['message'])
-        self.assertFalse('from_name' in data['message'])
-
-    def test_send_template_without_from_field_api_failure(self):
-        self.mock_post.return_value = self.MockResponse(status_code=400)
-        msg = mail.EmailMessage('Subject', 'Text Body',
-            'from@example.com', ['to@example.com'])
-        msg.template_name = "PERSONALIZED_SPECIALS"
-        msg.use_template_from = True
-        with self.assertRaises(AnymailAPIError):
-            msg.send()
-
-    def test_send_template_without_subject_field(self):
-        msg = mail.EmailMessage('Subject', 'Text Body',
-            'from@example.com', ['to@example.com'])
-        msg.template_name = "PERSONALIZED_SPECIALS"
-        msg.use_template_subject = True
-        msg.send()
-        self.assert_mandrill_called("/messages/send-template.json")
-        data = self.get_api_call_data()
-        self.assertEqual(data['template_name'], "PERSONALIZED_SPECIALS")
-        self.assertFalse('subject' in data['message'])
-
-    def test_no_template_content(self):
-        # Just a template, without any template_content to be merged
-        msg = mail.EmailMessage('Subject', 'Text Body',
-            'from@example.com', ['to@example.com'])
-        msg.template_name = "WELCOME_MESSAGE"
-        msg.send()
-        self.assert_mandrill_called("/messages/send-template.json")
-        data = self.get_api_call_data()
-        self.assertEqual(data['template_name'], "WELCOME_MESSAGE")
-        self.assertEqual(data['template_content'], [])  # Mandrill requires this field
-
-    def test_non_template_send(self):
-        # Make sure the non-template case still uses /messages/send.json
-        msg = mail.EmailMessage('Subject', 'Text Body',
-            'from@example.com', ['to@example.com'])
-        msg.send()
-        self.assert_mandrill_called("/messages/send.json")
-        data = self.get_api_call_data()
-        self.assertFalse('template_name' in data)
-        self.assertFalse('template_content' in data)
-        self.assertFalse('async' in data)
diff --git a/anymail/tests/test_mandrill_session_sharing.py b/anymail/tests/test_mandrill_session_sharing.py
deleted file mode 100644
index ba128ee..0000000
--- a/anymail/tests/test_mandrill_session_sharing.py
+++ /dev/null
@@ -1,72 +0,0 @@
-from decimal import Decimal
-from mock import patch
-
-from django.core import mail
-
-from .mock_backend import DjrillBackendMockAPITestCase
-
-
-class DjrillSessionSharingTests(DjrillBackendMockAPITestCase):
-    """Test Djrill backend sharing of single Mandrill API connection"""
-
-    @patch('requests.Session.close', autospec=True)
-    def test_connection_sharing(self, mock_close):
-        """Djrill reuses one requests session when sending multiple messages"""
-        datatuple = (
-            ('Subject 1', 'Body 1', 'from@example.com', ['to@example.com']),
-            ('Subject 2', 'Body 2', 'from@example.com', ['to@example.com']),
-        )
-        mail.send_mass_mail(datatuple)
-        self.assertEqual(self.mock_post.call_count, 2)
-        session1 = self.mock_post.call_args_list[0][0]  # arg[0] (self) is session
-        session2 = self.mock_post.call_args_list[1][0]
-        self.assertEqual(session1, session2)
-        self.assertEqual(mock_close.call_count, 1)
-
-    @patch('requests.Session.close', autospec=True)
-    def test_caller_managed_connections(self, mock_close):
-        """Calling code can created long-lived connection that it opens and closes"""
-        connection = mail.get_connection()
-        connection.open()
-        mail.send_mail('Subject 1', 'body', 'from@example.com', ['to@example.com'], connection=connection)
-        session1 = self.mock_post.call_args[0]
-        self.assertEqual(mock_close.call_count, 0)  # shouldn't be closed yet
-
-        mail.send_mail('Subject 2', 'body', 'from@example.com', ['to@example.com'], connection=connection)
-        self.assertEqual(mock_close.call_count, 0)  # still shouldn't be closed
-        session2 = self.mock_post.call_args[0]
-        self.assertEqual(session1, session2)  # should have reused same session
-
-        connection.close()
-        self.assertEqual(mock_close.call_count, 1)
-
-    def test_session_closed_after_exception(self):
-        # fail loud case:
-        msg = mail.EmailMessage('Subject', 'Message', 'from@example.com', ['to1@example.com'],)
-        msg.global_merge_vars = {'PRICE': Decimal('19.99')}  # will cause JSON serialization error
-        with patch('requests.Session.close', autospec=True) as mock_close:
-            with self.assertRaises(TypeError):
-                msg.send()
-        self.assertEqual(mock_close.call_count, 1)
-
-        # fail silently case (EmailMessage caches backend on send, so must create new one):
-        msg = mail.EmailMessage('Subject', 'Message', 'from@example.com', ['to1@example.com'],)
-        msg.global_merge_vars = {'PRICE': Decimal('19.99')}
-        with patch('requests.Session.close', autospec=True) as mock_close:
-            sent = msg.send(fail_silently=True)
-            self.assertEqual(sent, 0)
-        self.assertEqual(mock_close.call_count, 1)
-
-        # caller-supplied connection case:
-        with patch('requests.Session.close', autospec=True) as mock_close:
-            connection = mail.get_connection()
-            connection.open()
-            msg = mail.EmailMessage('Subject', 'Message', 'from@example.com', ['to1@example.com'],
-                                    connection=connection)
-            msg.global_merge_vars = {'PRICE': Decimal('19.99')}
-            with self.assertRaises(TypeError):
-                msg.send()
-            self.assertEqual(mock_close.call_count, 0)  # wait for us to close it
-
-            connection.close()
-            self.assertEqual(mock_close.call_count, 1)
diff --git a/anymail/tests/test_mandrill_subaccounts.py b/anymail/tests/test_mandrill_subaccounts.py
deleted file mode 100644
index 2f1880d..0000000
--- a/anymail/tests/test_mandrill_subaccounts.py
+++ /dev/null
@@ -1,27 +0,0 @@
-from django.core import mail
-from django.test.utils import override_settings
-
-from .mock_backend import DjrillBackendMockAPITestCase
-
-
-class DjrillMandrillSubaccountTests(DjrillBackendMockAPITestCase):
-    """Test Djrill backend support for Mandrill subaccounts"""
-
-    def test_no_subaccount_by_default(self):
-        mail.send_mail('Subject', 'Body', 'from@example.com', ['to@example.com'])
-        data = self.get_api_call_data()
-        self.assertFalse('subaccount' in data['message'])
-
-    @override_settings(ANYMAIL_MANDRILL_SEND_DEFAULTS={'subaccount': 'test_subaccount'})
-    def test_subaccount_setting(self):
-        mail.send_mail('Subject', 'Body', 'from@example.com', ['to@example.com'])
-        data = self.get_api_call_data()
-        self.assertEqual(data['message']['subaccount'], "test_subaccount")
-
-    @override_settings(ANYMAIL_MANDRILL_SEND_DEFAULTS={'subaccount': 'global_setting_subaccount'})
-    def test_subaccount_message_overrides_setting(self):
-        message = mail.EmailMessage('Subject', 'Body', 'from@example.com', ['to@example.com'])
-        message.subaccount = "individual_message_subaccount"  # should override global setting
-        message.send()
-        data = self.get_api_call_data()
-        self.assertEqual(data['message']['subaccount'], "individual_message_subaccount")
diff --git a/anymail/tests/test_postmark_backend.py b/anymail/tests/test_postmark_backend.py
index 0d4ec5b..1ecd88a 100644
--- a/anymail/tests/test_postmark_backend.py
+++ b/anymail/tests/test_postmark_backend.py
@@ -16,7 +16,7 @@ from anymail.exceptions import (AnymailAPIError, AnymailSerializationError,
                                 AnymailUnsupportedFeature, AnymailRecipientsRefused)
 from anymail.message import attach_inline_image_file
 
-from .mock_requests_backend import RequestsBackendMockAPITestCase
+from .mock_requests_backend import RequestsBackendMockAPITestCase, SessionSharingTestCasesMixin
 from .utils import sample_image_content, sample_image_path, SAMPLE_IMAGE_FILENAME, AnymailTestMixin, decode_att
 
 
@@ -517,6 +517,11 @@ class PostmarkBackendRecipientsRefusedTests(PostmarkBackendMockAPITestCase):
         self.assertEqual(status.recipients['spam@example.com'].status, 'rejected')
 
 
+class PostmarkBackendSessionSharingTestCase(SessionSharingTestCasesMixin, PostmarkBackendMockAPITestCase):
+    """Requests session sharing tests"""
+    pass  # tests are defined in the mixin
+
+
 @override_settings(ANYMAIL_SEND_DEFAULTS={
     'tags': ['globaltag'],
     'track_opens': True,
diff --git a/anymail/tests/test_sendgrid_backend.py b/anymail/tests/test_sendgrid_backend.py
index 2c83926..387500b 100644
--- a/anymail/tests/test_sendgrid_backend.py
+++ b/anymail/tests/test_sendgrid_backend.py
@@ -18,7 +18,7 @@ from django.utils.timezone import get_fixed_timezone, override as override_curre
 from anymail.exceptions import AnymailAPIError, AnymailSerializationError, AnymailUnsupportedFeature
 from anymail.message import attach_inline_image_file
 
-from .mock_requests_backend import RequestsBackendMockAPITestCase
+from .mock_requests_backend import RequestsBackendMockAPITestCase, SessionSharingTestCasesMixin
 from .utils import sample_image_content, sample_image_path, SAMPLE_IMAGE_FILENAME, AnymailTestMixin
 
 
@@ -487,6 +487,11 @@ class SendGridBackendRecipientsRefusedTests(SendGridBackendMockAPITestCase):
     pass
 
 
+class SendGridBackendSessionSharingTestCase(SessionSharingTestCasesMixin, SendGridBackendMockAPITestCase):
+    """Requests session sharing tests"""
+    pass  # tests are defined in the mixin
+
+
 @override_settings(ANYMAIL_SEND_DEFAULTS={
     'metadata': {'global': 'globalvalue', 'other': 'othervalue'},
     'tags': ['globaltag'],