SendGrid: support multiple reply_to

Closes #325

CHANGELOG.rst

@@ -53,6 +53,8 @@ Features
 * **Brevo (Sendinblue):** Add support for inbound email. (See
   `docs <https://anymail.dev/en/latest/esps/sendinblue/#sendinblue-inbound>`_.)
 
+* **SendGrid:** Support for multiple ``reply_to`` addresses.
+  (Thanks to `@gdvalderrama`_ for pointing out the new API.)
 
 Deprecations
 ~~~~~~~~~~~~
@@ -1546,6 +1548,7 @@ Features
 .. _@ewingrj: https://github.com/ewingrj
 .. _@fdemmer: https://github.com/fdemmer
 .. _@Flexonze: https://github.com/Flexonze
+.. _@gdvalderrama: https://github.com/gdvalderrama
 .. _@Honza-m: https://github.com/Honza-m
 .. _@janneThoft: https://github.com/janneThoft
 .. _@jc-ee: https://github.com/jc-ee

anymail/backends/sendgrid.py

@@ -254,11 +254,8 @@ def set_subject(self, subject):
             self.data["subject"] = subject
 
     def set_reply_to(self, emails):
-        # SendGrid only supports a single address in the reply_to API param.
-        if len(emails) > 1:
-            self.unsupported_feature("multiple reply_to addresses")
-        if len(emails) > 0:
-            self.data["reply_to"] = self.email_object(emails[0])
+        if emails:
+            self.data["reply_to_list"] = [self.email_object(email) for email in emails]
 
     def set_extra_headers(self, headers):
         # SendGrid requires header values to be strings -- not integers.

docs/esps/sendgrid.rst

@@ -202,14 +202,6 @@ Limitations and quirks
       webhook :attr:`message_id` will fall back to "smtp-id" when "anymail_id"
       isn't present.)
 
-**Single Reply-To**
-  SendGrid's v3 API only supports a single Reply-To address.
-
-  If your message has multiple reply addresses, you'll get an
-  :exc:`~anymail.exceptions.AnymailUnsupportedFeature` error---or
-  if you've enabled :setting:`ANYMAIL_IGNORE_UNSUPPORTED_FEATURES`,
-  Anymail will use only the first one.
-
 **Invalid Addresses**
   SendGrid will accept *and send* just about anything as
   a message's :attr:`from_email`. (And email protocols are

tests/test_sendgrid_backend.py

@@ -187,7 +187,7 @@ def test_email_message(self):
         self.assertEqual(
             data["content"], [{"type": "text/plain", "value": "Body goes here"}]
         )
-        self.assertEqual(data["reply_to"], {"email": "another@example.com"})
+        self.assertEqual(data["reply_to_list"], [{"email": "another@example.com"}])
         self.assertEqual(
             data["headers"],
             {
@@ -243,7 +243,8 @@ def test_extra_headers(self):
         # Reply-To must be moved to separate param
         self.assertNotIn("Reply-To", data["headers"])
         self.assertEqual(
-            data["reply_to"], {"name": "Do Not Reply", "email": "noreply@example.com"}
+            data["reply_to_list"],
+            [{"name": "Do Not Reply", "email": "noreply@example.com"}],
         )
 
     def test_extra_headers_serialization_error(self):
@@ -252,35 +253,20 @@ def test_extra_headers_serialization_error(self):
             self.message.send()
 
     def test_reply_to(self):
-        self.message.reply_to = ['"Reply recipient" <reply@example.com']
-        self.message.send()
-        data = self.get_api_call_json()
-        self.assertEqual(
-            data["reply_to"], {"name": "Reply recipient", "email": "reply@example.com"}
-        )
-
-    def test_multiple_reply_to(self):
-        # SendGrid v3 prohibits Reply-To in custom headers,
-        # and only allows a single reply address
-        self.message.reply_to = [
-            '"Reply recipient" <reply@example.com',
-            "reply2@example.com",
-        ]
-        with self.assertRaises(AnymailUnsupportedFeature):
-            self.message.send()
-
-    @override_settings(ANYMAIL_IGNORE_UNSUPPORTED_FEATURES=True)
-    def test_multiple_reply_to_ignore_unsupported(self):
-        # Should use first Reply-To if ignoring unsupported features
         self.message.reply_to = [
             '"Reply recipient" <reply@example.com',
             "reply2@example.com",
         ]
         self.message.send()
         data = self.get_api_call_json()
         self.assertEqual(
-            data["reply_to"], {"name": "Reply recipient", "email": "reply@example.com"}
+            data["reply_to_list"],
+            [
+                {"name": "Reply recipient", "email": "reply@example.com"},
+                {"email": "reply2@example.com"},
+            ],
         )
+        self.assertNotIn("reply_to", data)  # not allowed with reply_to_list
 
     def test_attachments(self):
         text_content = "* Item one\n* Item two\n* Item three"
@@ -1050,6 +1036,8 @@ def test_default_omits_options(self):
         self.assertNotIn("headers", data)
         self.assertNotIn("ip_pool_name", data)
         self.assertNotIn("mail_settings", data)
+        self.assertNotIn("reply_to", data)
+        self.assertNotIn("reply_to_list", data)
         self.assertNotIn("sections", data)
         self.assertNotIn("send_at", data)
         self.assertNotIn("template_id", data)

tests/test_sendgrid_integration.py

@@ -82,8 +82,7 @@ def test_all_options(self):
             to=["to1@sink.sendgrid.net", '"Recipient 2, OK?" <to2@sink.sendgrid.net>'],
             cc=["cc1@sink.sendgrid.net", "Copy 2 <cc2@sink.sendgrid.net>"],
             bcc=["bcc1@sink.sendgrid.net", "Blind Copy 2 <bcc2@sink.sendgrid.net>"],
-            # v3 only supports single reply-to:
-            reply_to=['"Reply, with comma" <reply@example.com>'],
+            reply_to=['"Reply, with comma" <reply@example.com>', "reply2@example.com"],
             headers={"X-Anymail-Test": "value", "X-Anymail-Count": 3},
             metadata={"meta1": "simple string", "meta2": 2},
             send_at=send_at,