----- Original Message ----- > From: "Wietse Venema" <wie...@porcupine.org> > To: "Wiebe Cazemier" <wi...@halfgaar.net> > Cc: postfix-users@postfix.org > Sent: Friday, 10 June, 2011 2:50:34 PM > Subject: Re: unverified_recipient_tempfail_action = permit > > Wiebe Cazemier: > > - The server is backup MX for mail hosts that I don't know anything > > about. > > In that case, the backup MX needs to ask the primary MX if the > recipient is valid. Otherwise, you become a backscatter source. > > Wietse >
But how can it do that when the primary server is down and while not deferring the incoming request?