cpython/Doc/library/smtpd.rst

:mod:`!smtpd` --- SMTP Server
=============================

.. module:: smtpd
   :synopsis: Removed in 3.12.
   :deprecated:

.. deprecated-removed:: 3.6 3.12

This module is no longer part of the Python standard library.
It was :ref:`removed in Python 3.12 <whatsnew312-removed>` after
being deprecated in Python 3.6.  The removal was decided in :pep:`594`.

A possible replacement is the third-party :pypi:`aiosmtpd` library. This
library is not maintained or supported by the Python core team.

The last version of Python that provided the :mod:`!smtpd` module was
`Python 3.11 <https://docs.python.org/3.11/library/smtpd.html>`_.