Dear maintainer(s),

In Python 3.5.4, smtpd has been formally marked as deprecated. Code that
imports this library will no longer work from Python 3.12, which is
currently in Trixie.

Since fail2ban use this Python library, please prepare for this removal
and migrate away from them.

See this link for more details:
https://peps.python.org/pep-0594/#deprecated-modules

Cheers,