The domains are not defined under mydestination, they are defined under virtual_alias_domains. So it sounds like the fallback_transport may not work for us. Is there any other way to accomplish that same scenario?
=lc ________________________________ From: owner-postfix-us...@postfix.org <owner-postfix-us...@postfix.org> on behalf of Viktor Dukhovni <postfix-us...@dukhovni.org> Sent: Wednesday, December 27, 2017 5:31 PM To: Postfix users Subject: Re: question on fallback transport usage > On Dec 27, 2017, at 5:15 PM, l carr <pandorasbo...@outlook.com> wrote: > > What we would like to do, as a transitional state, is mimic the Sendmail > failover relay to re-direct undeliverable email from the Postfix system to > Server A. With Server A only handling emails redirected to it from the > Postfix server, this would allow us to more easily identify the edge cases. > > We think we could do this using fallback transport but before we go too deep, > we'd like to see if anyone else has tried that and if it's a good idea or if > anyone has a better way to tackle that scenario. In our scenario, we would > only use the fallback transport until we completed migrating to the new > system. The "fallback_transport" setting is a feature of the local(8) delivery agent, when it finds no alias or local user matching the localpart of the email address. If all the problem messages are for a domain in mydestination, and fail to find a matching "alias" in local delivery, then indeed fallback_transport might do the trick. -- Viktor.