[Mailman-Developers] Fixing DMARC problems with .invalid munge

[John Levine]

>Exactly how to patch this depends on what Mailman version you're
>starting with, but you basically want some code like this.
>
>    name, addrs = parseaddr(msg.get('from'))
>    addrs += '.invalid'
>    del msg['from']
>    msg['From'] = formataddr((name, addrs))
>
>If you put it in Mailman/Handlers/Cleanse.py or
>Mailman/Handlers/CookHeaders.py, parseaddr and formataddr are already
>imported from email.Utils so the above 4 lines added to the
>process(mlist, msg, msgdata) function are all you need.

How do you limit it to just addresses with DMARC problems?  There's no
benefit to doing it to everyone.

R's,
John

PS: My experiments have been with mj2 because I know the code better.