From 441c9b007f50b288c5298491376ecae72a124e6e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Rapha=C3=ABl=20Droz?= <raphael.droz+floss@gmail.com>
Date: Wed, 11 May 2022 11:57:16 -0300
Subject: [PATCH] SMTP Transport to provide the (final) Message-ID if available

---
 .../Mailer/Transport/Smtp/SmtpTransport.php   | 30 ++++++++++++++++++-
 1 file changed, 29 insertions(+), 1 deletion(-)

diff --git a/src/Symfony/Component/Mailer/Transport/Smtp/SmtpTransport.php b/src/Symfony/Component/Mailer/Transport/Smtp/SmtpTransport.php
index 9432be7f3645f..5ac4b2dbdaa98 100644
--- a/src/Symfony/Component/Mailer/Transport/Smtp/SmtpTransport.php
+++ b/src/Symfony/Component/Mailer/Transport/Smtp/SmtpTransport.php
@@ -38,6 +38,7 @@ class SmtpTransport extends AbstractTransport
     private int $pingThreshold = 100;
     private float $lastMessageTime = 0;
     private AbstractStream $stream;
+    private string $mtaResult = '';
     private string $domain = '[127.0.0.1]';
 
     public function __construct(AbstractStream $stream = null, EventDispatcherInterface $dispatcher = null, LoggerInterface $logger = null)
@@ -146,11 +147,38 @@ public function send(RawMessage $message, Envelope $envelope = null): ?SentMessa
             throw $e;
         }
 
+        $messageId = $this->parseMessageId($this->mtaResult);
+        if ($messageId) {
+            $message->setMessageId($messageId);
+        }
+
         $this->checkRestartThreshold();
 
         return $message;
     }
 
+    protected function parseMessageId(string $mtaResult): ?string
+    {
+        $regexps = [
+            '/250 Ok (?P<id>[0-9a-f-]+)\r?$/mis',
+            '/250 Ok:? queued as (?P<id>[A-Z0-9]+)\r?$/mis'
+        ];
+
+        if ($mtaResult === '') {
+            return null;
+        }
+
+        $matches = [];
+        foreach ($regexps as $regexp) {
+            preg_match($regexp, $mtaResult, $matches);
+            if (!empty($matches['id'])) {
+                return $matches['id'];
+            }
+        }
+
+        return null;
+    }
+
     public function __toString(): string
     {
         if ($this->stream instanceof SocketStream) {
@@ -213,7 +241,7 @@ protected function doSend(SentMessage $message): void
                 $this->getLogger()->debug(sprintf('Email transport "%s" stopped', __CLASS__));
                 throw $e;
             }
-            $this->executeCommand("\r\n.\r\n", [250]);
+            $this->mtaResult = $this->executeCommand("\r\n.\r\n", [250]);
             $message->appendDebug($this->stream->getDebug());
             $this->lastMessageTime = microtime(true);
         } catch (TransportExceptionInterface $e) {