I'm thinking about hacking on a before queue proxy filter, but the link to suggested perl framework at http://www.postfix.org/SMTPD_PROXY_README.html seems dead. I googled "Bennett Todd smtp proxy", which brings mee to a git repo last updated five years ago.
What is the current best starting point for hacking a proxy filter? I'm running debian stretch on the mail-server, but I believe that would be irrelevant in this case, as pulling a pre-packaged .deb would only create extra clutter.
