On Wed, Apr 13, 2022 at 10:04:59PM -0400, John Levine wrote: > >in other words if a domain is nullMx postfix still reject it, aswell for > >senders > > Not all MTAs work the same.
Not even Postfix :-) By default mail is accepted from NullMX envelope sender domains, to reject it one must elect to use "reject_unknown_sender_domain". -- Viktor.