>> I understand it can't send it anywhere (at least in my case, if the
>> relayhost rejects the message, there's nowhere to send the message
>> and/or the bounce), but can't it save the email in some local file,
>> at least?
>> Especially when the email originated locally (i.e. was not received via
>> SMTP but via /usr/sbin/sendmail)?
> Postfix is a Mail TRANSFER Agent; it is not a Mail STORAGE Agent. Think of
> it like a bricks and mortar post office and mail. If mail is undeliverable,
> it is returned to the return address. Once returned, the post office is done
> with it; the post office does not archive a copy.
Sounds fine to me.
> If the mail cannot be returned to the return address, it is for all
> practical purposes discarded.
That describes the behavior I see, but in the case where the mail
originates locally, this behavior is clearly suboptimal: When the origin
of the message is /usr/sbin/sendmail, it doesn't seem completely
far-fetched to consider that the return-address is a local file.
When the message does not originate locally, Postfix's behavior seems
acceptable, since storing the bounced&unreturnable message locally might
not be very helpful: the sender may not have access to this machine and
might not even know on which machine his email ended up.
But when it originates locally, it would seem eminently helpful, since
any such bounced&unreturnable message would itself likely indicate
a misconfiguration, so it makes sense to keep those email around until
the configuration is fixed.
If you don't want such a behavior by default, that's fine, but I can
assure you that it would be very helpful for some of your users.
Otherwise, some (potentially very minor or temporary) config problem can
result in throwing away very valuable, carefully crafted messages, with
no way to recover them, even if the misconfiguration is detected
very quickly.
I think an MTA's n°1 responsibility is not to lose messages, and usually
Postfix is pretty good at it. What I'm asking is not hard to implement
and doesn't seem to have much subtle negative side-effects.
Stefan
