Vincent Pelletier: > Hello, > > I have a Mailman + postfix setup (old versions: mailman 2.1.11, > postfix 2.5.5), and the mail server of one of subscribers' domain > started rejecting mails when "From" header domain is its own domain > (foo.com MX rejecting incoming @foo.com mails). This of course happens > when a @foo.com member posts to the list: other @foo.com subscribers > never receive his post.
I suspect that they are enforcing a DMARC policy that requires modifications to list managers so that they replace the From: header address with the sender address of the mailing list. Google for "dmarc mailman fix". Wietse