Issue ARC signing not working for mailman mailing lists

[kastor]

It does not work on mails from mailman delivered by smtpdirect.
Ubuntu 20.04, Mailman 2.1.29, last Plesk updated installed.
ARC somehow works when a mail address has Forwarding switched on. The forwarding mail is ARC signed.
Any chance to get this working also for mailman?

 

[VNick]

Yes, currently it's not supported for Mailman. There's a chance it won't be supported for Mailman 2 at all.

 

[Alex Presland]

When I (previously) used Mailman 2 lists, there were 2 configuration settings which both involved the word "munge". Effectively, they munge the message so it isn't being forwarded and is represented as being ORIGINATED from the mailing list. At this point it all just worked.

My suggestion is that you get yourself into the detailed Mailman configuration and find these. I've found on DEV/DMARC - Mailman Wiki the following advice, which lists these two settings:

Hope that helps?

Sadly if you're sending to a host with volumes that make it insist upon ARC, I'm not sure that this will work or not.