[Dovecot] Dovecot discards mail over quota

[mouss]

Sahil Tandon a écrit :
> On Sun, 18 Jan 2009, Gary V wrote:
> 
>> On 1/17/09, Timo Sirainen wrote:
>>  > On Jan 17, 2009, at 2:36 PM, Gary V wrote:
>>  > > Then a bounce is created stating the mail was rejected:
>>  > >
>>  > > Your message to <test at example.com> was automatically rejected:
>>  > > Quota exceeded (mailbox for user is full).
>>  > >
>>  > > Question: is it possible (without changing code) to alter this to
>>  > > where deliver would instead tempfail or something. Somehow it seems
>>  > > wrong to me to tell the MTA that everything is good, and then silently
>>  > > discard messages - regardless of the fact dovecot creates a bounce.
>>  > > This is not necessarily ideal either, but I _am_ wondering if this is
>>  > > configurable or not.
>>  > >
>>  >
>>  > a) deliver -e
>>  >
>>  > b) quota_full_tempfail=yes
>>  >
>>  > c) a+b
>>  >
>>
>> Just as a matter of interest. On my Postfix system:
>>
>> a) Using deliver -e, Postfix bounces the message immediately 5.7.0 ->
>> Subject: Undelivered Mail Returned to Sender. Partial body:
>> "<test at example.com>: permission denied. Command output: Quota exceeded
>> (mailbox for user is full)". Postfix does not retain the message.
>>
>> b) quota_full_tempfail=yes: defers the message with 4.3.0. If the user
>> makes room for the message, then it will eventually be delivered. If
>> they don't, then _eventually_ a bounce will be sent. In this case the
>> bounce is less informative. Partial body: "<test at example.com>:
>> temporary failure". In the case where the message is not delivered,
>> using default settings in Postfix, the sender will be notified 5 days
>> after they sent the message.
>>
>> c) For over quota with a+b, it behaves the same way as b, but the
>> bounce notice will be more informative: Partial body:
>> "<test at example.com>: temporary failure. Command output: Quota exceeded
>> (mailbox for user is full)".
>>
>> I would say this is expected.
>>
>> Each of the four possibilites has advantages and disadvantages, and
>> personally I think a) might be closest to "doing the right thing", but
>> it would be cool to have the option of deferring the mail (using
>> option a+b) and additionally have deliver immediately send a message
>> to the sender notifying them that their mail has been delayed due to
>> the recipient being over quota. Something like:
> 
> I prefer a) because it does not involve backscatter in the case of spoofed
> sender addresses.
> 

that doesn't help. postfix has already accepted and queued the message.
so there be backscatter...

This brings one issue: a bounce should not be generated if the message
was tagged as spam by a content filter (X-Spam-Flag, X-Bogosity,
X-DSPAM-Result, ...).