This module offers several classes to implement SMTP (email) servers.
+.. seealso::
+
+ The `aiosmtpd <http://aiosmtpd.readthedocs.io/>`_ package is a recommended
+ replacement for this module. It is based on :mod:`asyncio` and provides a
+ more straightforward API. :mod:`smtpd` should be considered deprecated.
+
Several server implementations are present; one is a generic
do-nothing implementation, which can be overridden, while the other two offer
specific mail-sending strategies.
Documentation
-------------
+- bpo-25008: Document smtpd.py as effectively deprecated and add a pointer to
+ aiosmtpd, a third-party asyncio-based replacement.
+
- Issue #26355: Add canonical header link on each page to corresponding major
version of the documentation. Patch by Matthias Bussonnier.