[Dovecot] Dovecot discards mail over quota

[Sahil Tandon]

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.

-- 
Sahil Tandon <sahil at tandon.net>