> Am 2013-04-19 12:28, schrieb nullnullachtfuenfz...@arcor.de: > > The problem arises with mail originating from senders in > > @B2.example.com to recipients in @A1.example.com. > > Because the destination server in A also does a > > smtpd_sender_restrictions=reject_unknown_sender_domain and > > @B2.example.com is unknown in A´s DNS the sender address is rejected. > > The missing MX Record in A´s DNS is ok, because senders in > > @B2.example.com are not supposed to participate mail exchange with > > @A1.example.com and vice versa. > > But where to deliver the bounce? > Why exactly is there a bounce in the first place? If the @A1 MX rejects > mail from @B2 during the SMTP session, it never receives responsibility > for any bounces. Unless of course you accept the mail first and then > decide later to bounce it. But why would you do that? >
Timo you opened my eyes. We have the same DNS information as the destination host has. With smtpd_sender_restrictions=reject_unknown_sender_domain activated in this postfix instance the problem silently disappears. Thanks a lot Peter
