From 9370179c15492a785cfd0ada3ebb0b9f4b1fdb04 Mon Sep 17 00:00:00 2001
From: Javier Eguiluz <javier.eguiluz@gmail.com>
Date: Mon, 9 Dec 2019 17:21:53 +0100
Subject: [PATCH] [Mailer] Mentioned the getMessageId() method

---
 mailer.rst | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/mailer.rst b/mailer.rst
index acf196c0ebc..fc19a02e914 100644
--- a/mailer.rst
+++ b/mailer.rst
@@ -271,6 +271,17 @@ provides access to the original message (``getOriginalMessage()``) and to some
 debug information (``getDebug()``) such as the HTTP calls done by the HTTP
 transports, which is useful to debug errors.
 
+.. note::
+
+    Some mailer providers change the ``Message-Id`` when sending the email. The
+    ``getMessageId()`` method from ``SentMessage`` always returns the definitive
+    ID of the message (being the original random ID generated by Symfony or the
+    new ID generated by the mailer provider).
+
+    .. versionadded:: 4.4
+
+        The ``getMessageId()`` method was introduced in Symfony 4.4.
+
 The exceptions related to mailer transports (those which implement
 :class:`Symfony\\Component\\Mailer\\Exception\\TransportException`) also provide
 this debug information via the ``getDebug()`` method.