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Doc/library/superseded.rst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 They have been superseded by other modules.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

@@ -126,6 +126,14 @@ 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
+  :keyword:`async`/:keyword:`await`-based server instead.
+  (Contributed by Oleg Iarygin in :gh:`93243`.)
+
+.. _aiosmtpd: https://pypi.org/project/aiosmtpd/
+
 
 Porting to Python 3.12
 ======================
@@ -151,6 +159,10 @@ Changes in the Python API
   select from a larger range than ``randrange(10**25)``.
   (Originally suggested by Serhiy Storchaka gh-86388.)
 
+* Removed the strictly synchronous ``smtpd`` module, deprecated in Python 3.4.7
+  and 3.5.4.  A recommended replacement is the
+  :keyword:`async`/:keyword:`await`-based aiosmtpd_ PyPI module.
+
 
 Build Changes
 =============

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/test/test_logging.py

@@ -60,9 +60,10 @@
 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: