Hi all, I have made Mailman work mostly with DKIM (and therefore DMARC). The one remaining trick is this: Mailman will "simplify" mail addresses in Cc (and maybe From and To) headers in some circumstances - which breaks DKIM signatures.
So, for an email address like: Name <addr...@example.com> if the "Name" is missing, Mailman will remove the "<" and ">". To get around this, you can either always put a "Name", or lease out both the "Name" and the "<>". Sorry for the pain, hopefully most people can fix this in their address books etc. And to be clear, this only matters where the originating site uses DMARC with a strict policy (which includes samba.org). -- Cheers, Stephen Rothwell