On 07/04/2022 17:55, Pedro David Marco wrote:
Probably i am misunderstanding Postfix documentation but... What is exactly the
Postfix criteria about using smtp_fallback_relay ????
I also had an issue with this some time ago, which I didn't understand.
At the time I had set the fallback relay as the smart-host of my ISP.
Postfix offered a message to the (correct) direct destination and was
grey-listed.
Postfix immediately resent the message via the fallback relay.
I felt that this behaviour mimicked some of the larger ISPs which resend
messages using a different IP address every time, and which never got past the
grey-list. I thought that this was "wrong" and - at the time - removed the
fallback directive.
What I *WANTED* was only to use the fallback if Postfix could not resolve a
direct IP address. There are probably issues with this, too; if the address is
unresolvable for me, it is likely to be unresolvable for my ISP also.
What are the optimum settings for these circumstances?
Thanks
Allen C
