[8.x] Change to X-Message-ID in Mailgun and Ses Transport (#34567)

* Change to X-Message-ID in mail transport

* Fixed incorrect usage of addTextHeader

* Updated test for 'X-Message-ID'

* Updated test for X-Message-ID in SesTransport

* Fixed code syntax

* Update MailgunTransport.php

* Update SesTransport.php

* Update MailSesTransportTest.php

Co-authored-by: Taylor Otwell <taylor@laravel.com>

src/Illuminate/Mail/Transport/MailgunTransport.php

@@ -72,9 +72,10 @@ public function send(Swift_Mime_SimpleMessage $message, &$failedRecipients = nul
             $this->payload($message, $to)
         );
 
-        $message->getHeaders()->addTextHeader(
-            'X-Mailgun-Message-ID', $this->getMessageId($response)
-        );
+        $messageId = $this->getMessageId($response);
+
+        $message->getHeaders()->addTextHeader('X-Message-ID', $messageId);
+        $message->getHeaders()->addTextHeader('X-Mailgun-Message-ID', $messageId);
 
         $message->setBcc($bcc);
 

src/Illuminate/Mail/Transport/SesTransport.php

@@ -52,7 +52,10 @@ public function send(Swift_Mime_SimpleMessage $message, &$failedRecipients = nul
             )
         );
 
-        $message->getHeaders()->addTextHeader('X-SES-Message-ID', $result->get('MessageId'));
+        $messageId = $result->get('MessageId');
+
+        $message->getHeaders()->addTextHeader('X-Message-ID', $messageId);
+        $message->getHeaders()->addTextHeader('X-SES-Message-ID', $messageId);
 
         $this->sendPerformed($message);
 

tests/Mail/MailSesTransportTest.php

@@ -52,7 +52,7 @@ public function testSend()
         $transport = new SesTransport($client);
 
         // Generate a messageId for our mock to return to ensure that the post-sent message
-        // has X-SES-Message-ID in its headers
+        // has X-Message-ID in its headers
         $messageId = Str::random(32);
         $sendRawEmailMock = new sendRawEmailMock($messageId);
         $client->expects($this->once())
@@ -64,6 +64,8 @@ public function testSend()
             ->willReturn($sendRawEmailMock);
 
         $transport->send($message);
+
+        $this->assertEquals($messageId, $message->getHeaders()->get('X-Message-ID')->getFieldBody());
         $this->assertEquals($messageId, $message->getHeaders()->get('X-SES-Message-ID')->getFieldBody());
     }
 }