diff --git a/anymail/utils.py b/anymail/utils.py
index 080a1f9..403b406 100644
--- a/anymail/utils.py
+++ b/anymail/utils.py
@@ -285,6 +285,7 @@ class Attachment:
             if self.content is None:
                 self.content = attachment.as_bytes()
             self.mimetype = attachment.get_content_type()
+            self.content_type = attachment["Content-Type"]  # includes charset if provided
 
             content_disposition = attachment.get_content_disposition()
             if content_disposition == 'inline' or (not content_disposition and 'Content-ID' in attachment):
@@ -294,6 +295,7 @@ class Attachment:
                     self.cid = unquote(self.content_id)  # without the <, >
         else:
             (self.name, self.content, self.mimetype) = attachment
+            self.content_type = self.mimetype
 
         self.name = force_non_lazy(self.name)
         self.content = force_non_lazy(self.content)
@@ -304,6 +306,8 @@ class Attachment:
             self.mimetype, _ = mimetypes.guess_type(self.name)
         if self.mimetype is None:
             self.mimetype = DEFAULT_ATTACHMENT_MIME_TYPE
+        if self.content_type is None:
+            self.content_type = self.mimetype
 
     @property
     def b64content(self):
diff --git a/tests/test_utils.py b/tests/test_utils.py
index d8a3f9b..161a7fb 100644
--- a/tests/test_utils.py
+++ b/tests/test_utils.py
@@ -4,6 +4,7 @@ import base64
 import copy
 import pickle
 from email.mime.image import MIMEImage
+from email.mime.text import MIMEText
 
 from django.http import QueryDict
 from django.test import SimpleTestCase, RequestFactory, override_settings
@@ -217,6 +218,11 @@ class NormalizedAttachmentTests(SimpleTestCase):
         self.assertFalse(att.inline)
         self.assertIsNone(att.content_id)  # ignored for non-inline Attachment
 
+    def test_content_type(self):
+        att = Attachment(MIMEText("text", "plain", "iso8859-1"), "ascii")
+        self.assertEqual(att.mimetype, "text/plain")
+        self.assertEqual(att.content_type, 'text/plain; charset="iso8859-1"')
+
 
 class LazyCoercionTests(SimpleTestCase):
     """Test utils.is_lazy and force_non_lazy*"""