Maillist/mailgroup restrictions - use contact E-Mail instead of Primary EMail

Hi Folks,

we’re using email lists and try to activate listfilter feature. We found that use_sasl_username=false will check senders address to filter incomming mail. But from our understanding users primary email address will be checked.

Would it be also possible to allow receiving mails based on users contact email address additional / instead of primary?

hope this can be done somehow.