[Mailer] add ability to disable the TLS peer verification via DSN

Author: Livda

components/mailer.rst

@@ -142,6 +142,17 @@ The mailer will start using the first transport and if it fails, it will retry
 the same delivery with the next transports until one of them succeeds (or until
 all of them fail).
 
+Disable TLS peer verification
+-----------------------------
+
+Symfony's mailer supports TLS peer verification by default, but in some cases, 
+this verification shouldn't be done, like if the SMTP server has a self signed 
+certificate.
+
+In such case, a parameter can be used in the DSN::
+
+    $dsn = 'smtp://user:pass@smtp.example.com?verify_peer=false'
+
 Sending emails asynchronously
 -----------------------------