gh-93243: Make smtpd private before porting its users

Doc/library/email.rst

@@ -147,6 +147,3 @@ Legacy API:
    Module :mod:`mailbox`
       Tools for creating, reading, and managing collections of messages on disk
       using a variety standard formats.
-
-   Module :mod:`smtpd`
-      SMTP server framework (primarily useful for testing)

Doc/library/superseded.rst

@@ -27,7 +27,6 @@ backwards compatibility. They have been superseded by other modules.
    optparse.rst
    ossaudiodev.rst
    pipes.rst
-   smtpd.rst
    sndhdr.rst
    spwd.rst
    sunau.rst

Doc/whatsnew/3.12.rst

@@ -299,6 +299,14 @@ Removed
   (and corresponding ``EXPERIMENTAL_ISOLATED_SUBINTERPRETERS``)
   have been removed.
 
+* ``smtpd`` has been removed according to the schedule in :pep:`594`,
+  having been deprecated in Python 3.4.7 and 3.5.4.
+  Use aiosmtpd_ PyPI module or any other
+  :mod:`asyncio`-based server instead.
+  (Contributed by Oleg Iarygin in :gh:`93243`.)
+
+.. _aiosmtpd: https://pypi.org/project/aiosmtpd/
+
 * Remove ``io.OpenWrapper`` and ``_pyio.OpenWrapper``, deprecated in Python
   3.10: just use :func:`open` instead. The :func:`open` (:func:`io.open`)
   function is a built-in function. Since Python 3.10, :func:`_pyio.open` is
@@ -382,6 +390,10 @@ Changes in the Python API
   to :term:`filesystem encoding and error handler`.
   Argument files should be encoded in UTF-8 instead of ANSI Codepage on Windows.
 
+* Removed the ``asyncore``-based ``smtpd`` module deprecated in Python 3.4.7
+  and 3.5.4.  A recommended replacement is the
+  :mod:`asyncio`-based aiosmtpd_ PyPI module.
+
 * :func:`shlex.split`: Passing ``None`` for *s* argument now raises an
   exception, rather than reading :data:`sys.stdin`. The feature was deprecated
   in Python 3.9.

Lib/test/mock_socket.py

@@ -1,4 +1,4 @@
-"""Mock socket module used by the smtpd and smtplib tests.
+"""Mock socket module used by the smtplib tests.
 """
 
 # imported for _GLOBAL_DEFAULT_TIMEOUT
@@ -33,7 +33,7 @@ def close(self):
 
 
 class MockSocket:
-    """Mock socket object used by smtpd and smtplib tests.
+    """Mock socket object used by the smtplib tests.
     """
     def __init__(self, family=None):
         global _reply_data

Lib/smtpd.py → Lib/test/smtpd.py

@@ -77,25 +77,16 @@
 import time
 import socket
 import collections
-from warnings import _deprecated, warn
+from test.support.import_helper import import_module
+from warnings import warn
 from email._header_value_parser import get_addr_spec, get_angle_addr
 
 __all__ = [
     "SMTPChannel", "SMTPServer", "DebuggingServer", "PureProxy",
 ]
 
-_DEPRECATION_MSG = ('The {name} module is deprecated and unmaintained and will '
-                    'be removed in Python {remove}.  Please see aiosmtpd '
-                    '(https://aiosmtpd.readthedocs.io/) for the recommended '
-                    'replacement.')
-_deprecated(__name__, _DEPRECATION_MSG, remove=(3, 12))
-
-
-# These are imported after the above warning so that users get the correct
-# deprecation warning.
-import asyncore
-import asynchat
-
+asyncore = import_module('asyncore', deprecated=True)
+asynchat = import_module('asynchat', deprecated=True)
 
 program = sys.argv[0]
 __version__ = 'Python SMTP proxy version 0.3'

Lib/test/test_logging.py

@@ -61,9 +61,10 @@
 from socketserver import (ThreadingUDPServer, DatagramRequestHandler,
                           ThreadingTCPServer, StreamRequestHandler)
 
+with warnings.catch_warnings():
+    from . import smtpd
 
 asyncore = warnings_helper.import_deprecated('asyncore')
-smtpd = warnings_helper.import_deprecated('smtpd')
 
 
 try: