LMTP error on trying to find passwd-file for Postfix recipient validation

[Narcis Garcia]

__________
I'm using this dedicated address because personal addresses aren't 
masked enough at this mail public archive. Public archive administrator 
should fix this against automated addresses collectors.
El 28/1/22 a les 12:50, Bernardo Reino ha escrit:
> On Fri, 28 Jan 2022, Narcis Garcia wrote:
> 
>> Hello everyone,
>>
>> I have following configurations (and more) at /etc/dovecot/local.conf 
>> in a "/VirtualUserFlatFilesPostfix/" setup :
>>
>> [partial file content begins]
> 
> [snip]
> 
>> When incoming mail goes to a mailbox that does not exist, an error is 
>> logged by Dovecot, letter remains at Postfix queue, and no rejection 
>> message to sender (here host is /mail.example.net/):
> 
> Wouldn't it make sense to prevent postfix from attempting to deliver 
> (via LMTP) messages addressed to invalid users?
> 
> i.e. using virtual_mailbox_maps and/or virtual_alias_maps, as needed.
> 
>> [partial]$ cat /var/log/dovecot.log
>>
>> 2022-01-28 08:52:00 lmtp(1883): Info: Connect from local
>> 2022-01-28 08:52:00 auth: Error: passwd-file(wronguser at example.net): 
>> stat(/srv/vmail/domains.d/example.net/users.d/wronguser/etc/passwd) 
>> failed: Address family not supported by protocol
> 
> ^^^ weird message, but maybe it's dovecot's way of saying "file not 
> found" :)

My Postfix setup can't have all possible destination addresses 
registered because it does not only manage arrivals to local recipients 
but also does "domain relay" for some other FQDNs.
Then I feel Postfix needs to pass next service (Either SASL-lmtp or next 
MTA hop) to result in a "deliverable or not deliverable action".