diff --git a/addons/mail/tests/common.py b/addons/mail/tests/common.py
index 69bc85fc326..b5d609d09ba 100644
--- a/addons/mail/tests/common.py
+++ b/addons/mail/tests/common.py
@@ -111,6 +111,7 @@ class MockEmail(common.BaseCase, MockSmtplibCase):
              'smtp_host': 'smtp_host',
             }
         ])
+        cls.mail_servers = cls.mail_server_domain + cls.mail_server_global
 
     # ------------------------------------------------------------
     # GATEWAY TOOLS
@@ -507,6 +508,7 @@ class MockEmail(common.BaseCase, MockSmtplibCase):
         debug_info = '-'.join('From: %s-To: %s' % (mail['email_from'], mail['email_to']) for mail in self._mails) if not bool(sent_mail) else ''
         self.assertTrue(bool(sent_mail), 'Expected mail from %s to %s not found in %s' % (expected['email_from'], expected['email_to'], debug_info))
 
+        # assert values
         for val in direct_check:
             if val in expected:
                 self.assertEqual(expected[val], sent_mail[val], 'Value for %s: expected %s, received %s' % (val, expected[val], sent_mail[val]))
diff --git a/addons/test_mail/tests/test_mail_mail.py b/addons/test_mail/tests/test_mail_mail.py
index a992e039f7b..8a10c94fbb5 100644
--- a/addons/test_mail/tests/test_mail_mail.py
+++ b/addons/test_mail/tests/test_mail_mail.py
@@ -62,7 +62,7 @@ class TestMailMail(TestMailCommon):
     def _reset_data(self):
         self._init_mail_mock()
         self.test_mail.write({'failure_reason': False, 'failure_type': False, 'state': 'outgoing'})
-        self.test_notification.write({'failure_type': False, 'notification_status': 'ready'})
+        self.test_notification.write({'failure_reason': False, 'failure_type': False, 'notification_status': 'ready'})
 
     @users('admin')
     def test_mail_mail_attachment_access(self):
@@ -150,6 +150,46 @@ class TestMailMail(TestMailCommon):
         self.assertSentEmail(mail.env.user.partner_id, [self.user_employee.email_formatted])
         self.assertEqual(len(self._mails), 2)
 
+    @mute_logger('odoo.addons.mail.models.mail_mail')
+    def test_mail_mail_recipients_cc(self):
+        """ Partner_ids is a field used from mail_message, but not from mail_mail. """
+        mail = self.env['mail.mail'].sudo().create({
+            'body_html': '<p>Test</p>',
+            'email_cc': 'test.cc.1@example.com, "Herbert" <test.cc.2@example.com>',
+            'email_to': 'test.rec.1@example.com, "Raoul" <test.rec.2@example.com>',
+            'recipient_ids': [(4, self.user_employee.partner_id.id)],
+        })
+
+        with self.mock_mail_gateway():
+            mail.send()
+        # note that formatting is lost for cc
+        self.assertSentEmail(mail.env.user.partner_id,
+                             ['test.rec.1@example.com', '"Raoul" <test.rec.2@example.com>'],
+                             email_cc=['test.cc.1@example.com', 'test.cc.2@example.com'])
+        # Mail: currently cc are put as copy of all sent emails (aka spam)
+        self.assertSentEmail(mail.env.user.partner_id, [self.user_employee.email_formatted],
+                             email_cc=['test.cc.1@example.com', 'test.cc.2@example.com'])
+        self.assertEqual(len(self._mails), 2)
+
+    @mute_logger('odoo.addons.mail.models.mail_mail')
+    def test_mail_mail_recipients_formatting(self):
+        """ Check support of email / formatted email """
+        mail = self.env['mail.mail'].sudo().create({
+            'author_id': False,
+            'body_html': '<p>Test</p>',
+            'email_cc': 'test.cc.1@example.com, "Herbert" <test.cc.2@example.com>',
+            'email_from': '"Ignasse" <test.from@example.com>',
+            'email_to': 'test.rec.1@example.com, "Raoul" <test.rec.2@example.com>',
+        })
+
+        with self.mock_mail_gateway():
+            mail.send()
+        # note that formatting is lost for cc
+        self.assertSentEmail('"Ignasse" <test.from@example.com>',
+                             ['test.rec.1@example.com', '"Raoul" <test.rec.2@example.com>'],
+                             email_cc=['test.cc.1@example.com', 'test.cc.2@example.com'])
+        self.assertEqual(len(self._mails), 1)
+
     @mute_logger('odoo.addons.mail.models.mail_mail')
     def test_mail_mail_return_path(self):
         # mail without thread-enabled record
@@ -235,11 +275,14 @@ class TestMailMail(TestMailCommon):
         with self.mock_mail_gateway(), mute_logger('odoo.addons.mail.models.mail_mail'):
             mail.send(raise_exception=False)
         self.assertFalse(self._mails[0]['email_from'])
-        self.assertIn(
-            'You must either provide a sender address explicitly or configure using the combination of `mail.catchall.domain` and `mail.default.from` ICPs',
-            mail.failure_reason)
+        self.assertEqual(
+            mail.failure_reason,
+            'You must either provide a sender address explicitly or configure using the combination of `mail.catchall.domain` and `mail.default.from` ICPs, in the server configuration file or with the --email-from startup parameter.')
         self.assertFalse(mail.failure_type, 'Mail: void from: no failure type, should be updated')
         self.assertEqual(mail.state, 'exception')
+        self.assertEqual(
+            notification.failure_reason,
+            'You must either provide a sender address explicitly or configure using the combination of `mail.catchall.domain` and `mail.default.from` ICPs, in the server configuration file or with the --email-from startup parameter.')
         self.assertEqual(notification.failure_type, 'unknown', 'Mail: void from: unknown failure type, should be updated')
         self.assertEqual(notification.notification_status, 'exception')
 
@@ -254,6 +297,7 @@ class TestMailMail(TestMailCommon):
         self.assertIn('Codepoint U+00A2 at position', mail.failure_reason)
         self.assertFalse(mail.failure_type, 'Mail: bugged from (ascii): no failure type, should be updated')
         self.assertEqual(mail.state, 'exception')
+        self.assertIn('Codepoint U+00A2 at position', notification.failure_reason)
         self.assertEqual(notification.failure_type, 'unknown', 'Mail: bugged from (ascii): unknown failure type, should be updated')
         self.assertEqual(notification.notification_status, 'exception')
 
@@ -267,6 +311,7 @@ class TestMailMail(TestMailCommon):
         self.assertIn('Codepoint U+00A2 at position', mail.failure_reason)
         self.assertFalse(mail.failure_type, 'Mail: bugged catchall domain (ascii): no failure type, should be updated')
         self.assertEqual(mail.state, 'exception')
+        self.assertIn('Codepoint U+00A2 at position', notification.failure_reason)
         self.assertEqual(notification.failure_type, 'unknown', 'Mail: bugged catchall domain (ascii): unknown failure type, should be updated')
         self.assertEqual(notification.notification_status, 'exception')
 
@@ -277,9 +322,10 @@ class TestMailMail(TestMailCommon):
         with self.mock_mail_gateway():
             mail.send(raise_exception=False)
         self.assertEqual(self._mails[0]['email_from'], 'robert')
-        self.assertIn("Malformed 'Return-Path' or 'From' address: robert", mail.failure_reason)
+        self.assertEqual(mail.failure_reason, "Malformed 'Return-Path' or 'From' address: robert - It should contain one valid plain ASCII email")
         self.assertFalse(mail.failure_type, 'Mail: bugged from (ascii): no failure type, should be updated')
         self.assertEqual(mail.state, 'exception')
+        self.assertEqual(notification.failure_reason, "Malformed 'Return-Path' or 'From' address: robert - It should contain one valid plain ASCII email")
         self.assertEqual(notification.failure_type, 'unknown', 'Mail: bugged from (ascii): unknown failure type, should be updated')
         self.assertEqual(notification.notification_status, 'exception')
 
@@ -298,13 +344,15 @@ class TestMailMail(TestMailCommon):
             mail.write({'email_to': email_to})
             with self.mock_mail_gateway():
                 mail.send(raise_exception=False)
-            self.assertIn('Error without exception. Probably due to sending an email without computed recipients.', mail.failure_reason)
+            self.assertEqual(mail.failure_reason, 'Error without exception. Probably due to sending an email without computed recipients.')
             self.assertFalse(mail.failure_type, 'Mail: missing email_to: no failure type, should be updated')
             self.assertEqual(mail.state, 'exception')
             if email_to == ' ':
+                self.assertFalse(notification.failure_reason, 'Mail: failure reason not propagated')
                 self.assertEqual(notification.failure_type, 'mail_email_missing')
                 self.assertEqual(notification.notification_status, 'exception')
             else:
+                self.assertFalse(notification.failure_reason, 'Mail: failure reason not propagated')
                 self.assertEqual(notification.failure_type, False, 'Mail: missing email_to: notification is wrongly set as sent')
                 self.assertEqual(notification.notification_status, 'sent', 'Mail: missing email_to: notification is wrongly set as sent')
 
@@ -315,9 +363,10 @@ class TestMailMail(TestMailCommon):
             mail.write({'email_to': email_to})
             with self.mock_mail_gateway():
                 mail.send(raise_exception=False)
-            self.assertIn('Error without exception. Probably due to sending an email without computed recipients.', mail.failure_reason)
+            self.assertEqual(mail.failure_reason, 'Error without exception. Probably due to sending an email without computed recipients.')
             self.assertFalse(mail.failure_type, 'Mail: invalid email_to: no failure type, should be updated')
             self.assertEqual(mail.state, 'exception')
+            self.assertFalse(notification.failure_reason, 'Mail: failure reason not propagated')
             self.assertEqual(notification.failure_type, failure_type, 'Mail: invalid email_to: missing instead of invalid')
             self.assertEqual(notification.notification_status, 'exception')
 
@@ -330,6 +379,7 @@ class TestMailMail(TestMailCommon):
             self.assertIn('Codepoint U+00A2 at position', mail.failure_reason)
             self.assertFalse(mail.failure_type, 'Mail: invalid (ascii) recipient partner: no failure type, should be updated')
             self.assertEqual(mail.state, 'exception')
+            self.assertIn('Codepoint U+00A2 at position', notification.failure_reason)
             self.assertEqual(notification.failure_type, 'unknown', 'Mail: invalid (ascii) recipient partner: unknown failure type, should be updated')
             self.assertEqual(notification.notification_status, 'exception')
 
@@ -342,6 +392,7 @@ class TestMailMail(TestMailCommon):
             self.assertFalse(mail.failure_reason)
             self.assertFalse(mail.failure_type)
             self.assertEqual(mail.state, 'sent')
+            self.assertFalse(notification.failure_reason)
             self.assertFalse(notification.failure_type)
             self.assertEqual(notification.notification_status, 'sent')
 
@@ -379,6 +430,7 @@ class TestMailMail(TestMailCommon):
             self.assertEqual(mail.failure_reason, 'Error without exception. Probably due to sending an email without computed recipients.')
             self.assertFalse(mail.failure_type, 'Mail: void recipient partner: no failure type, should be updated')
             self.assertEqual(mail.state, 'exception')
+            self.assertFalse(notification.failure_reason, 'Mail: failure reason not propagated')
             self.assertEqual(notification.failure_type, 'mail_email_invalid', 'Mail: void recipient partner: should be missing, not invalid')
             self.assertEqual(notification.notification_status, 'exception')
 
@@ -392,6 +444,7 @@ class TestMailMail(TestMailCommon):
             self.assertEqual(mail.failure_reason, 'Error without exception. Probably due to sending an email without computed recipients.')
             self.assertFalse(mail.failure_type, 'Mail: invalid recipient partner: no failure type, should be updated')
             self.assertEqual(mail.state, 'exception')
+            self.assertFalse(notification.failure_reason, 'Mail: failure reason not propagated')
             self.assertEqual(notification.failure_type, 'mail_email_invalid')
             self.assertEqual(notification.notification_status, 'exception')
 
@@ -405,6 +458,7 @@ class TestMailMail(TestMailCommon):
             self.assertIn('Codepoint U+00A2 at position', mail.failure_reason)
             self.assertFalse(mail.failure_type, 'Mail: invalid (ascii) recipient partner: no failure type, should be updated')
             self.assertEqual(mail.state, 'exception')
+            self.assertIn('Codepoint U+00A2 at position', notification.failure_reason)
             self.assertEqual(notification.failure_type, 'unknown', 'Mail: invalid (ascii) recipient partner: unknown failure type, should be updated')
             self.assertEqual(notification.notification_status, 'exception')
 
@@ -418,6 +472,7 @@ class TestMailMail(TestMailCommon):
             self.assertFalse(mail.failure_reason)
             self.assertFalse(mail.failure_type)
             self.assertEqual(mail.state, 'sent')
+            self.assertFalse(notification.failure_reason)
             self.assertFalse(notification.failure_type)
             self.assertEqual(notification.notification_status, 'sent')
 
@@ -451,6 +506,7 @@ class TestMailMail(TestMailCommon):
             self.assertFalse(mail.failure_reason, 'Mail: at least one valid recipient, mail is sent to avoid send loops and spam')
             self.assertFalse(mail.failure_type, 'Mail: at least one valid recipient, mail is sent to avoid send loops and spam')
             self.assertEqual(mail.state, 'sent', 'Mail: at least one valid recipient, mail is sent to avoid send loops and spam')
+            self.assertFalse(notification.failure_reason, 'Mail: void email considered as invalid')
             self.assertEqual(notification.failure_type, 'mail_email_invalid', 'Mail: void email considered as invalid')
             self.assertEqual(notification.notification_status, 'exception')
 
@@ -468,30 +524,34 @@ class TestMailMail(TestMailCommon):
         # missing to / invalid to
         for email_to in self.emails_falsy + self.emails_invalid:
             self._reset_data()
-            notification2.write({'failure_type': False, 'notification_status': 'ready'})
+            notification2.write({'failure_reason': False, 'failure_type': False, 'notification_status': 'ready'})
             mail.write({'email_to': email_to})
             with self.mock_mail_gateway():
                 mail.send(raise_exception=False)
             self.assertFalse(mail.failure_reason, 'Mail: at least one valid recipient, mail is sent to avoid send loops and spam')
             self.assertFalse(mail.failure_type, 'Mail: at least one valid recipient, mail is sent to avoid send loops and spam')
             self.assertEqual(mail.state, 'sent', 'Mail: at least one valid recipient, mail is sent to avoid send loops and spam')
+            self.assertFalse(notification.failure_reason)
             self.assertFalse(notification.failure_type)
             self.assertEqual(notification.notification_status, 'sent')
+            self.assertFalse(notification2.failure_reason)
             self.assertEqual(notification2.failure_type, 'mail_email_invalid')
             self.assertEqual(notification2.notification_status, 'exception')
 
         # buggy to (ascii)
         for email_to in self.emails_invalid_ascii:
             self._reset_data()
-            notification2.write({'failure_type': False, 'notification_status': 'ready'})
+            notification2.write({'failure_reason': False, 'failure_type': False, 'notification_status': 'ready'})
             mail.write({'email_to': email_to})
             with self.mock_mail_gateway():
                 mail.send(raise_exception=False)
             self.assertIn('Codepoint U+00A2 at position', mail.failure_reason)
             self.assertFalse(mail.failure_type, 'Mail: at least one valid recipient, mail is sent to avoid send loops and spam')
             self.assertEqual(mail.state, 'exception')
+            self.assertIn('Codepoint U+00A2 at position', notification.failure_reason)
             self.assertEqual(notification.failure_type, 'unknown')
             self.assertEqual(notification.notification_status, 'exception')
+            self.assertIn('Codepoint U+00A2 at position', notification2.failure_reason)
             self.assertEqual(notification2.failure_type, 'unknown')
             self.assertEqual(notification2.notification_status, 'exception')
 
@@ -521,9 +581,10 @@ class TestMailMail(TestMailCommon):
                 self.connect_mocked.side_effect = _connect
 
                 mail.send(raise_exception=False)
-                self.assertFalse(mail.failure_type)
                 self.assertEqual(mail.failure_reason, msg)
+                self.assertFalse(mail.failure_type)
                 self.assertEqual(mail.state, 'exception')
+                self.assertFalse(notification.failure_reason, 'Mail: failure reason not propagated')
                 self.assertEqual(notification.failure_type, 'mail_smtp')
                 self.assertEqual(notification.notification_status, 'exception')
                 self._reset_data()
@@ -549,6 +610,7 @@ class TestMailMail(TestMailCommon):
                 self.assertFalse(mail.failure_reason, 'SMTPServerDisconnected/MemoryError during Send raises and lead to a rollback')
                 self.assertFalse(mail.failure_type, 'SMTPServerDisconnected/MemoryError during Send raises and lead to a rollback')
                 self.assertEqual(mail.state, 'outgoing', 'SMTPServerDisconnected/MemoryError during Send raises and lead to a rollback')
+                self.assertFalse(notification.failure_reason, 'SMTPServerDisconnected/MemoryError during Send raises and lead to a rollback')
                 self.assertFalse(notification.failure_type, 'SMTPServerDisconnected/MemoryError during Send raises and lead to a rollback')
                 self.assertEqual(notification.notification_status, 'ready', 'SMTPServerDisconnected/MemoryError during Send raises and lead to a rollback')
 
@@ -566,6 +628,7 @@ class TestMailMail(TestMailCommon):
                 self.assertEqual(mail.failure_reason, msg)
                 self.assertFalse(mail.failure_type, 'Mail: unlogged failure type to fix')
                 self.assertEqual(mail.state, 'exception')
+                self.assertEqual(notification.failure_reason, msg)
                 self.assertEqual(notification.failure_type, 'unknown', 'Mail: generic failure type')
                 self.assertEqual(notification.notification_status, 'exception')
 
diff --git a/addons/test_mail/tests/test_performance.py b/addons/test_mail/tests/test_performance.py
index 1c29eb29943..a47adb8e1f3 100644
--- a/addons/test_mail/tests/test_performance.py
+++ b/addons/test_mail/tests/test_performance.py
@@ -698,26 +698,68 @@ class TestMailComplexPerformance(BaseMailPerformance):
     @warmup
     def test_complex_mail_mail_send(self):
         message = self.env['mail.message'].sudo().create({
-            'subject': 'Test',
-            'body': '<p>Test</p>',
             'author_id': self.env.user.partner_id.id,
+            'body': '<p>Test</p>',
             'email_from': self.env.user.partner_id.email,
+            'message_type': 'comment',
             'model': 'mail.test.container',
             'res_id': self.container.id,
+            'subject': 'Test',
         })
+        attachments = self.env['ir.attachment'].create([
+            dict(attachment, res_id=self.container.id, res_model='mail.test.container')
+            for attachment in self.test_attachments_vals
+        ])
         mail = self.env['mail.mail'].sudo().create({
+            'attachment_ids': [(4, att.id) for att in attachments],
+            'auto_delete': False,
             'body_html': '<p>Test</p>',
             'mail_message_id': message.id,
             'recipient_ids': [(4, pid) for pid in self.partners.ids],
         })
-        mail_ids = mail.ids
         with self.assertQueryCount(__system__=9, employee=9):
-            self.env['mail.mail'].sudo().browse(mail_ids).send()
+            self.env['mail.mail'].sudo().browse(mail.ids).send()
 
-        self.assertEqual(mail.body_html, '<p>Test</p>')
-        self.assertEqual(mail.reply_to, formataddr(
-            ('%s %s' % (self.env.company.name, self.container.name), 'test-alias@%s' % self.alias_domain)
-        ))
+    @mute_logger('odoo.tests', 'odoo.addons.mail.models.mail_mail', 'odoo.models.unlink')
+    @users('__system__', 'employee')
+    @warmup
+    def test_complex_mail_mail_send_batch_complete(self):
+        """ A more complete use case: 10 mails, attachments, servers, ... And
+        2 failing emails. """
+        message = self.env['mail.message'].sudo().create({
+            'author_id': self.env.user.partner_id.id,
+            'email_from': self.env.user.partner_id.email,
+            'message_type': 'comment',
+            'model': 'mail.test.container',
+            'res_id': self.container.id,
+            'subject': 'Test',
+        })
+        attachments = self.env['ir.attachment'].create([
+            dict(attachment, res_id=self.container.id, res_model='mail.test.container')
+            for attachment in self.test_attachments_vals
+        ])
+        mails = self.env['mail.mail'].sudo().create([{
+            'attachment_ids': [(4, att.id) for att in attachments],
+            'auto_delete': True,
+            'body_html': '<p>Test %s</p>' % idx,
+            'email_cc': 'cc.1@test.example.com, cc.2@test.example.com',
+            'email_to': 'customer.1@example.com, customer.2@example.com',
+            'mail_message_id': message.id,
+            'mail_server_id': self.mail_servers.ids[idx % len(self.mail_servers.ids)],
+            'recipient_ids': [(4, pid) for pid in self.partners.ids],
+        } for idx in range(12)])
+        mails[-2].write({'email_cc': False, 'email_to': 'strange@example¢¡.com'})
+        mails[-1].write({'email_cc': False, 'email_to': 'void', 'recipient_ids': [(5, 0)]})
+        with self.assertQueryCount(__system__=44, employee=44):
+            self.env['mail.mail'].sudo().browse(mails.ids).send()
+
+        for mail in mails[:-2]:
+            self.assertEqual(mail.state, 'sent')
+            self.assertTrue(mail.to_delete, 'Mail: sent mails are to be unlinked')
+        self.assertEqual(mails[-2].state, 'exception')
+        self.assertFalse(mails[-2].to_delete, 'Mail: invalid recipient, not to unlink')
+        self.assertEqual(mails[-1].state, 'exception')
+        self.assertFalse(mails[-2].to_delete, 'Mail: ninvalid recipient, not to unlink')
 
     @mute_logger('odoo.tests', 'odoo.addons.mail.models.mail_mail', 'odoo.models.unlink')
     @users('__system__', 'employee')