diff --git a/tests/test_mailgun_integration.py b/tests/test_mailgun_integration.py
index 3d0b982..0017ef3 100644
--- a/tests/test_mailgun_integration.py
+++ b/tests/test_mailgun_integration.py
@@ -37,8 +37,8 @@ class MailgunBackendIntegrationTests(SimpleTestCase, AnymailTestMixin):
 
     def setUp(self):
         super(MailgunBackendIntegrationTests, self).setUp()
-        self.message = AnymailMessage('Anymail integration test', 'Text content',
-                                      'from@example.com', ['to@example.com'])
+        self.message = AnymailMessage('Anymail Mailgun integration test', 'Text content',
+                                      'from@example.com', ['anymail-test-to1@mailinator.com'])
         self.message.attach_alternative('<p>HTML content</p>', "text/html")
 
     def fetch_mailgun_events(self, message_id, event=None,
@@ -87,8 +87,8 @@ class MailgunBackendIntegrationTests(SimpleTestCase, AnymailTestMixin):
         self.assertEqual(sent_count, 1)
 
         anymail_status = self.message.anymail_status
-        sent_status = anymail_status.recipients['to@example.com'].status
-        message_id = anymail_status.recipients['to@example.com'].message_id
+        sent_status = anymail_status.recipients['anymail-test-to1@mailinator.com'].status
+        message_id = anymail_status.recipients['anymail-test-to1@mailinator.com'].message_id
 
         self.assertEqual(sent_status, 'queued')  # Mailgun always queues
         self.assertGreater(len(message_id), 0)  # don't know what it'll be, but it should exist
@@ -100,12 +100,12 @@ class MailgunBackendIntegrationTests(SimpleTestCase, AnymailTestMixin):
         send_at = datetime.now().replace(microsecond=0) + timedelta(minutes=2)
         send_at_timestamp = mktime(send_at.timetuple())  # python3: send_at.timestamp()
         message = AnymailMessage(
-            subject="Anymail all-options integration test",
+            subject="Anymail Mailgun all-options integration test",
             body="This is the text body",
             from_email="Test From <from@example.com>, also-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>"],
+            to=["anymail-test-to1@mailinator.com", "Recipient 2 <anymail-test-to2@mailinator.com>"],
+            cc=["anymail-test-cc1@mailinator.com", "Copy 2 <anymail-test-cc2@mailinator.com>"],
+            bcc=["anymail-test-bcc1@mailinator.com", "Blind Copy 2 <anymail-test-bcc2@mailinator.com>"],
             reply_to=["reply1@example.com", "Reply 2 <reply2@example.com>"],
             headers={"X-Anymail-Test": "value"},
 
@@ -137,13 +137,15 @@ class MailgunBackendIntegrationTests(SimpleTestCase, AnymailTestMixin):
                          {"meta1": "simple string", "meta2": "2"})  # all metadata values become strings
 
         self.assertEqual(event["message"]["scheduled-for"], send_at_timestamp)
-        self.assertIn(event["recipient"], ['to1@example.com', 'to2@example.com', 'cc1@example.com',
-                                           'cc2@example.com', 'bcc1@example.com', 'bcc2@example.com'])
+        self.assertIn(event["recipient"], ['anymail-test-to1@mailinator.com', 'anymail-test-to2@mailinator.com',
+                                           'anymail-test-cc1@mailinator.com', 'anymail-test-cc1@mailinator.com',
+                                           'anymail-test-bcc1@mailinator.com', 'anymail-test-bcc2@mailinator.com'])
 
         headers = event["message"]["headers"]
         self.assertEqual(headers["from"], "Test From <from@example.com>, also-from@example.com")
-        self.assertEqual(headers["to"], "to1@example.com, Recipient 2 <to2@example.com>")
-        self.assertEqual(headers["subject"], "Anymail all-options integration test")
+        self.assertEqual(headers["to"],
+                         "anymail-test-to1@mailinator.com, Recipient 2 <anymail-test-to2@mailinator.com>")
+        self.assertEqual(headers["subject"], "Anymail Mailgun all-options integration test")
 
         attachments = event["message"]["attachments"]
         self.assertEqual(len(attachments), 2)  # because inline image shouldn't be an attachment
diff --git a/tests/test_mailjet_integration.py b/tests/test_mailjet_integration.py
index 271e9da..e82d79c 100644
--- a/tests/test_mailjet_integration.py
+++ b/tests/test_mailjet_integration.py
@@ -39,7 +39,7 @@ class MailjetBackendIntegrationTests(SimpleTestCase, AnymailTestMixin):
     def setUp(self):
         super(MailjetBackendIntegrationTests, self).setUp()
         self.message = AnymailMessage('Anymail Mailjet integration test', 'Text content',
-                                      'test@test-mj.anymail.info', ['to@example.com'])
+                                      'test@test-mj.anymail.info', ['anymail-test-to1@mailinator.com'])
         self.message.attach_alternative('<p>HTML content</p>', "text/html")
 
     def test_simple_send(self):
@@ -48,8 +48,8 @@ class MailjetBackendIntegrationTests(SimpleTestCase, AnymailTestMixin):
         self.assertEqual(sent_count, 1)
 
         anymail_status = self.message.anymail_status
-        sent_status = anymail_status.recipients['to@example.com'].status
-        message_id = anymail_status.recipients['to@example.com'].message_id
+        sent_status = anymail_status.recipients['anymail-test-to1@mailinator.com'].status
+        message_id = anymail_status.recipients['anymail-test-to1@mailinator.com'].message_id
 
         self.assertEqual(sent_status, 'sent')
         self.assertRegex(message_id, r'.+')
@@ -58,12 +58,12 @@ class MailjetBackendIntegrationTests(SimpleTestCase, AnymailTestMixin):
 
     def test_all_options(self):
         message = AnymailMessage(
-            subject="Anymail all-options integration test",
+            subject="Anymail Mailjet all-options integration test",
             body="This is the text body",
             from_email='"Test Sender, Inc." <test@test-mj.anymail.info>',
-            to=['to1@example.com', '"Recipient, 2nd" <to2@example.com>'],
-            cc=['cc1@example.com', 'Copy 2 <cc2@example.com>'],
-            bcc=['bcc1@example.com', 'Blind Copy 2 <bcc2@example.com>'],
+            to=['anymail-test-to1@mailinator.com', '"Recipient, 2nd" <anymail-test-to2@mailinator.com>'],
+            cc=['anymail-test-cc1@mailinator.com', 'Copy 2 <anymail-test-cc1@mailinator.com>'],
+            bcc=['anymail-test-bcc1@mailinator.com', 'Blind Copy 2 <anymail-test-bcc2@mailinator.com>'],
             reply_to=['reply1@example.com', '"Reply, 2nd" <reply2@example.com>'],
             headers={"X-Anymail-Test": "value"},
 
@@ -85,14 +85,14 @@ class MailjetBackendIntegrationTests(SimpleTestCase, AnymailTestMixin):
 
     def test_merge_data(self):
         message = AnymailMessage(
-            subject="Anymail merge_data test",  # Mailjet doesn't support merge fields in the subject
+            subject="Anymail Mailjet merge_data test",  # Mailjet doesn't support merge fields in the subject
             body="This body includes merge data: [[var:value]]\n"
                  "And global merge data: [[var:global]]",
             from_email="Test From <test@test-mj.anymail.info>",
-            to=["to1@example.com", "Recipient 2 <to2@example.com>"],
+            to=["anymail-test-to1@mailinator.com", "Recipient 2 <anymail-test-to2@mailinator.com>"],
             merge_data={
-                'to1@example.com': {'value': 'one'},
-                'to2@example.com': {'value': 'two'},
+                'anymail-test-to1@mailinator.com': {'value': 'one'},
+                'anymail-test-to2@mailinator.com': {'value': 'two'},
             },
             merge_global_data={
                 'global': 'global_value'
@@ -100,15 +100,15 @@ class MailjetBackendIntegrationTests(SimpleTestCase, AnymailTestMixin):
         )
         message.send()
         recipient_status = message.anymail_status.recipients
-        self.assertEqual(recipient_status['to1@example.com'].status, 'sent')
-        self.assertEqual(recipient_status['to2@example.com'].status, 'sent')
+        self.assertEqual(recipient_status['anymail-test-to1@mailinator.com'].status, 'sent')
+        self.assertEqual(recipient_status['anymail-test-to2@mailinator.com'].status, 'sent')
 
     def test_stored_template(self):
         message = AnymailMessage(
             template_id='176375',  # ID of the real template named 'test-template' in our Mailjet test account
-            to=["to1@example.com"],
+            to=["anymail-test-to1@mailinator.com"],
             merge_data={
-                'to1@example.com': {
+                'anymail-test-to1@mailinator.com': {
                     'name': "Test Recipient",
                 }
             },
@@ -119,7 +119,7 @@ class MailjetBackendIntegrationTests(SimpleTestCase, AnymailTestMixin):
         message.from_email = None  # use the template's sender email/name
         message.send()
         recipient_status = message.anymail_status.recipients
-        self.assertEqual(recipient_status['to1@example.com'].status, 'sent')
+        self.assertEqual(recipient_status['anymail-test-to1@mailinator.com'].status, 'sent')
 
     @override_settings(ANYMAIL_MAILJET_API_KEY="Hey, that's not an API key!")
     def test_invalid_api_key(self):
diff --git a/tests/test_mandrill_integration.py b/tests/test_mandrill_integration.py
index 901fc78..2b09d9a 100644
--- a/tests/test_mandrill_integration.py
+++ b/tests/test_mandrill_integration.py
@@ -33,7 +33,7 @@ class MandrillBackendIntegrationTests(SimpleTestCase, AnymailTestMixin):
     def setUp(self):
         super(MandrillBackendIntegrationTests, self).setUp()
         self.message = mail.EmailMultiAlternatives('Anymail Mandrill integration test', 'Text content',
-                                                   'from@example.com', ['to@example.com'])
+                                                   'from@example.com', ['anymail-test-to1@mailinator.com'])
         self.message.attach_alternative('<p>HTML content</p>', "text/html")
 
     def test_simple_send(self):
@@ -43,8 +43,8 @@ class MandrillBackendIntegrationTests(SimpleTestCase, AnymailTestMixin):
 
         # noinspection PyUnresolvedReferences
         anymail_status = self.message.anymail_status
-        sent_status = anymail_status.recipients['to@example.com'].status
-        message_id = anymail_status.recipients['to@example.com'].message_id
+        sent_status = anymail_status.recipients['anymail-test-to1@mailinator.com'].status
+        message_id = anymail_status.recipients['anymail-test-to1@mailinator.com'].message_id
 
         self.assertIn(sent_status, ['sent', 'queued'])  # successful send (could still bounce later)
         self.assertGreater(len(message_id), 0)  # don't know what it'll be, but it should exist
@@ -54,12 +54,12 @@ class MandrillBackendIntegrationTests(SimpleTestCase, AnymailTestMixin):
 
     def test_all_options(self):
         message = AnymailMessage(
-            subject="Anymail all-options integration test",
+            subject="Anymail Mandrill 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>"],
+            to=["anymail-test-to1@mailinator.com", "Recipient 2 <anymail-test-to2@mailinator.com>"],
+            cc=["anymail-test-cc1@mailinator.com", "Copy 2 <anymail-test-cc2@mailinator.com>"],
+            bcc=["anymail-test-bcc1@mailinator.com", "Blind Copy 2 <anymail-test-bcc2@mailinator.com>"],
             reply_to=["reply1@example.com", "Reply 2 <reply2@example.com>"],
             headers={"X-Anymail-Test": "value"},
 
diff --git a/tests/test_postmark_integration.py b/tests/test_postmark_integration.py
index 433976b..2f652d4 100644
--- a/tests/test_postmark_integration.py
+++ b/tests/test_postmark_integration.py
@@ -22,17 +22,17 @@ class PostmarkBackendIntegrationTests(SimpleTestCase, AnymailTestMixin):
     def setUp(self):
         super(PostmarkBackendIntegrationTests, self).setUp()
         self.message = AnymailMessage('Anymail Postmark integration test', 'Text content',
-                                      'from@example.com', ['to@example.com'])
+                                      'from@example.com', ['anymail-test-to1@mailinator.com'])
         self.message.attach_alternative('<p>HTML content</p>', "text/html")
 
     def test_simple_send(self):
-        # Example of getting the SendGrid send status and message id from the message
+        # Example of getting the Postmark send status and message id from the message
         sent_count = self.message.send()
         self.assertEqual(sent_count, 1)
 
         anymail_status = self.message.anymail_status
-        sent_status = anymail_status.recipients['to@example.com'].status
-        message_id = anymail_status.recipients['to@example.com'].message_id
+        sent_status = anymail_status.recipients['anymail-test-to1@mailinator.com'].status
+        message_id = anymail_status.recipients['anymail-test-to1@mailinator.com'].message_id
 
         self.assertEqual(sent_status, 'sent')
         self.assertGreater(len(message_id), 0)  # non-empty string
@@ -41,13 +41,13 @@ class PostmarkBackendIntegrationTests(SimpleTestCase, AnymailTestMixin):
 
     def test_all_options(self):
         message = AnymailMessage(
-            subject="Anymail all-options integration test",
+            subject="Anymail Postmark all-options integration test",
             body="This is the text body",
             # Postmark accepts multiple from_email addresses, but truncates to the first on their end
             from_email="Test From <from@example.com>, also-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>"],
+            to=["anymail-test-to1@mailinator.com", "Recipient 2 <anymail-test-to2@mailinator.com>"],
+            cc=["anymail-test-cc1@mailinator.com", "Copy 2 <anymail-test-cc2@mailinator.com>"],
+            bcc=["anymail-test-bcc1@mailinator.com", "Blind Copy 2 <anymail-test-bcc2@mailinator.com>"],
             reply_to=["reply1@example.com", "Reply 2 <reply2@example.com>"],
             headers={"X-Anymail-Test": "value"},
 
diff --git a/tests/test_sendinblue_integration.py b/tests/test_sendinblue_integration.py
index 18bcd9b..fc31639 100644
--- a/tests/test_sendinblue_integration.py
+++ b/tests/test_sendinblue_integration.py
@@ -35,7 +35,7 @@ class SendinBlueBackendIntegrationTests(SimpleTestCase, AnymailTestMixin):
         super(SendinBlueBackendIntegrationTests, self).setUp()
 
         self.message = AnymailMessage('Anymail SendinBlue integration test', 'Text content',
-                                      'from@example.com', ['to@example.com'])
+                                      'from@test-sb.anymail.info', ['anymail-test-to1@mailinator.com'])
         self.message.attach_alternative('<p>HTML content</p>', "text/html")
 
     def test_simple_send(self):
@@ -44,8 +44,8 @@ class SendinBlueBackendIntegrationTests(SimpleTestCase, AnymailTestMixin):
         self.assertEqual(sent_count, 1)
 
         anymail_status = self.message.anymail_status
-        sent_status = anymail_status.recipients['to@example.com'].status
-        message_id = anymail_status.recipients['to@example.com'].message_id
+        sent_status = anymail_status.recipients['anymail-test-to1@mailinator.com'].status
+        message_id = anymail_status.recipients['anymail-test-to1@mailinator.com'].message_id
 
         self.assertEqual(sent_status, 'queued')  # SendinBlue always queues
         self.assertRegex(message_id, r'\<.+@.+\>')  # Message-ID can be ...@smtp-relay.mail.fr or .sendinblue.com
@@ -54,12 +54,12 @@ class SendinBlueBackendIntegrationTests(SimpleTestCase, AnymailTestMixin):
 
     def test_all_options(self):
         message = AnymailMessage(
-            subject="Anymail all-options integration test",
+            subject="Anymail SendinBlue all-options integration test",
             body="This is the text body",
-            from_email='"Test From, with comma" <from@example.com>',
-            to=["to1@example.com", '"Recipient 2, OK?" <to2@example.com>'],
-            cc=["cc1@example.com", "Copy 2 <cc2@example.com>"],
-            bcc=["bcc1@example.com", "Blind Copy 2 <bcc2@example.com>"],
+            from_email='"Test From, with comma" <from@test-sb.anymail.info>',
+            to=["anymail-test-to1@mailinator.com", '"Recipient 2, OK?" <anymail-test-to2@mailinator.com>'],
+            cc=["anymail-test-cc1@mailinator.com", "Copy 2 <anymail-test-cc2@mailinator.com>"],
+            bcc=["anymail-test-bcc1@mailinator.com", "Blind Copy 2 <anymail-test-bcc2@mailinator.com>"],
             reply_to=['"Reply, with comma" <reply@example.com>'],  # SendinBlue API v3 only supports single reply-to
             headers={"X-Anymail-Test": "value", "X-Anymail-Count": 3},
 
@@ -78,7 +78,7 @@ class SendinBlueBackendIntegrationTests(SimpleTestCase, AnymailTestMixin):
     def test_template(self):
         message = AnymailMessage(
             template_id=1,  # There is a template with this id in the Anymail test account
-            to=["to1@example.com"],  # SendinBlue doesn't allow recipient display names with templates
+            to=["anymail-test-to1@mailinator.com"],  # SendinBlue doesn't allow recipient display names with templates
             reply_to=["reply@example.com"],
             tags=["using-template"],
             headers={"X-Anymail-Test": "group: A, variation: C"},