More source links
diff --git a/Doc/library/smtplib.rst b/Doc/library/smtplib.rst
index 858301d..531a64d 100644
--- a/Doc/library/smtplib.rst
+++ b/Doc/library/smtplib.rst
@@ -10,6 +10,10 @@
pair: SMTP; protocol
single: Simple Mail Transfer Protocol
+**Source code:** :source:`Lib/smtplib.py`
+
+--------------
+
The :mod:`smtplib` module defines an SMTP client session object that can be used
to send mail to any Internet machine with an SMTP or ESMTP listener daemon. For
details of SMTP and ESMTP operation, consult :rfc:`821` (Simple Mail Transfer