Thanks Viktor, i do not pretend to bother anybody to the extent of reviewing logs... i justneed to understand smpt_fallback_relay a little bit more... thanks again for your kindness.. So... a soft fail in delivery is considered a "unreachable" destination, and hence, smtp_fallback_relaytakes place... my understanding was that unreacahble meant "cannot connect to remote smtp port"... Thanks again! Pete.
On Thursday, April 7, 2022, 07:52:43 PM GMT+2, Viktor Dukhovni <postfix-us...@dukhovni.org> wrote: On Thu, Apr 07, 2022 at 04:55:26PM +0000, Pedro David Marco wrote: > I have destinations not accepting email with a 451 return code. Some > of them are being sent by postfix to the smtp_fallback_relay and some > of them are just sent to the deferred queue... Probably i am > misunderstanding Postfix documentation but... What is exactly the > Postfix criteria about using smtp_fallback_relay ???? When at least one envelope recipient soft fails for all attempted connections and/or SMTP sessions, then connections are attempted to any configured fallback relays (for such remaining envelope recipients). No detailed analysis is possible without logs. If you post all the relevant log entries (including relevant messages from the "smtp" processes with same "pid" as the final defer log entry) then it'll be possible to disect the sequence of events for a particular delivery attempt. You may find the "collate" script useful: https://github.com/vdukhovni/postfix/tree/master/postfix/auxiliary/collate -- Viktor.