I've a server that handle a mail domain, debian jessie, clearly exim.
I've ever user a smarthost (the ISP one) to send email to final recipent,
with a custom configuration but heavy based on debian default one.
Recently i've changes ISP and so smarthost. Suddenly some aliases, that
redirect to some external email, bounced back ('unknown user').
Eg, in /etc/aliases an address like:
alias1: localuser
works as expected, while an alias like:
alias2: remoteuser@???
not.
After hitting my head on the wall for some time, i've used exim in address
verification mode, and found that simply exim do a callout, and the callout
for some reason fail. So the address are considered non-deliverable, and get
bounced (and negative-cached by exim).
If i set 'no_verify' for the alias router, i've found that verification
succeded and correctly stop on 'alias2', not expanding aliases (eg, if
alias2 exist, verify ok; if 'alias3' does not exist, fail verification).
What i expect from aliases.
But still i'm a bit confused; AFAIK verification on smarthost is disabled by
default, and anyway verification on trasport is only on domain, not the full
address (localpart@domain).
So, why aliases get full verified for smarthost?
Thanks.
--
e quanti pesci nelle orecchie adesso ho,
contarli forse si, levarli piu' non so. (R. Vecchioni)