symfony
diff --git a/‎src/Symfony/Component/Mailer/Transport/Smtp/SmtpTransport.php
Lines changed: 14 additions & 13 deletions b/‎src/Symfony/Component/Mailer/Transport/Smtp/SmtpTransport.php
Lines changed: 14 additions & 13 deletions
diff --git a/‎src/Symfony/Component/Mailer/Transport/Smtp/Stream/AbstractStream.php
Lines changed: 16 additions & 0 deletions b/‎src/Symfony/Component/Mailer/Transport/Smtp/Stream/AbstractStream.php
Lines changed: 16 additions & 0 deletions
@@ -135,7 +135,6 @@ public function send(RawMessage $message, SmtpEnvelope $envelope = null): ?SentM
      */
     public function executeCommand(string $command, array $codes): string
     {
-        $this->getLogger()->debug(sprintf('Email transport "%s" sent command "%s"', __CLASS__, trim($command)));
         $this->stream->write($command);
         $response = $this->getFullResponse();
         $this->assertResponseCode($response, $codes);
@@ -145,18 +144,22 @@ public function executeCommand(string $command, array $codes): string
 
     protected function doSend(SentMessage $message): void
     {
-        $envelope = $message->getEnvelope();
-        $this->doMailFromCommand($envelope->getSender()->toString());
-        foreach ($envelope->getRecipients() as $recipient) {
-            $this->doRcptToCommand($recipient->toString());
-        }
+        try {
+            $envelope = $message->getEnvelope();
+            $this->doMailFromCommand($envelope->getSender()->toString());
+            foreach ($envelope->getRecipients() as $recipient) {
+                $this->doRcptToCommand($recipient->toString());
+            }
 
-        $this->executeCommand("DATA\r\n", [354]);
-        foreach (AbstractStream::replace("\r\n.", "\r\n..", $message->toIterable()) as $chunk) {
-            $this->stream->write($chunk);
+            $this->executeCommand("DATA\r\n", [354]);
+            foreach (AbstractStream::replace("\r\n.", "\r\n..", $message->toIterable()) as $chunk) {
+                $this->stream->write($chunk);
+            }
+            $this->stream->flush();
+            $this->executeCommand("\r\n.\r\n", [250]);
+        } finally {
+            $message->appendDebug($this->stream->getDebug());
         }
-        $this->stream->flush();
-        $this->executeCommand("\r\n.\r\n", [250]);
     }
 
     protected function doHeloCommand(): void
@@ -237,8 +240,6 @@ private function assertResponseCode(string $response, array $codes): void
         list($code) = sscanf($response, '%3d');
         $valid = \in_array($code, $codes);
 
-        $this->getLogger()->debug(sprintf('Email transport "%s" received response "%s" (%s).', __CLASS__, trim($response), $valid ? 'ok' : 'error'));
-
         if (!$valid) {
             throw new TransportException(sprintf('Expected response code "%s" but got code "%s", with message "%s".', implode('/', $codes), $code, trim($response)), $code);
         }
 
@@ -28,8 +28,14 @@ abstract class AbstractStream
     protected $in;
     protected $out;
 
+    private $debug = '';
+
     public function write(string $bytes): void
     {
+        foreach (explode("\n", trim($bytes)) as $line) {
+            $this->debug .= sprintf("> %s\n", $line);
+        }
+
         $bytesToWrite = \strlen($bytes);
         $totalBytesWritten = 0;
         while ($totalBytesWritten < $bytesToWrite) {
@@ -74,9 +80,19 @@ public function readLine(): string
             }
         }
 
+        $this->debug .= sprintf('< %s', $line);
+
         return $line;
     }
 
+    public function getDebug(): string
+    {
+        $debug = $this->debug;
+        $this->debug = '';
+
+        return $debug;
+    }
+
     public static function replace(string $from, string $to, iterable $chunks): \Generator
     {
         if ('' === $from) {