Hi! We do have two external mail relays (MX 10 mx1 & MX 20 mx2) that accept mails for our domains, do lots of checks and relay them via a secure channel through the firewall into our network. Inside and outside we use postfix.
When sending mails out, we use the same way: send them from our internal network to one (mx1 only) of our mail relays via secure channel. This external postfix does - again - a lot of thing like DKIM etc. This outside postfix on mx1 then sends mails into the world. The internal postfix sends the mails to mx1 using "default_transport" (using a customized incarnation of smtp in master.cf). What we thought is that we could use mx2 for outgoing mails, too. This would be wise if mx1 is down (what sometimes really happen). But I find no setting like "fallback_default_transport" that can be used like default_transport in case our default_transport does not answer. Can anyone please tell me how we can establish a backup link to our mx2 working like default_transport for the cases where mx1 is not available? Thanks a lot! -lutzn -- Empfehlen Sie GMX DSL Ihren Freunden und Bekannten und wir belohnen Sie mit bis zu 50,- Euro! https://freundschaftswerbung.gmx.de
