dovecot - Aug 2012 - Dovecot generate file when over quota detected

Hi,

I am curious if Dovecot can add an empty file into a Maildir folder as 
soon as a mailbox has exceeded 100% capacity, and later when it detects 
the quota has fallen below 100% unlink the file. The idea is the Dovecot 
LDA would deliver the message and if this caused the mailbox to reach 
100%+, add a file into the maibox say "username/Maildir/overquota". 
Interactions via Dovecot IMAP/POP3 that lower the mailbox usage, for 
example the user popping, or deleting mail from the mailbox would 
trigger Dovecot to unlink the file.

This means that an MTA can efficiently check for the existence of this 
'overquota' file and return a "user at domain.com Mailbox
full" TEMPFAIL
error early during the SMTP transaction prior to accepting any data.

Dominic

On 23.8.2012, at 9.48, Dominic Malolepszy wrote:
> I am curious if Dovecot can add an empty file into a Maildir folder as soon
as a mailbox has exceeded 100% capacity, and later when it detects the quota has
fallen below 100% unlink the file. The idea is the Dovecot LDA would deliver the
message and if this caused the mailbox to reach 100%+, add a file into the
maibox say "username/Maildir/overquota". Interactions via Dovecot
IMAP/POP3 that lower the mailbox usage, for example the user popping, or
deleting mail from the mailbox would trigger Dovecot to unlink the file.
Quota warning scripts can do that.
http://wiki2.dovecot.org/Quota/Configuration#Quota_warnings

On 31/08/2012 11:40 PM, Timo Sirainen wrote:
> On 23.8.2012, at 9.48, Dominic Malolepszy wrote:
>
>> I am curious if Dovecot can add an empty file into a Maildir folder as
soon as a mailbox has exceeded 100% capacity, and later when it detects the
quota has fallen below 100% unlink the file. The idea is the Dovecot LDA would
deliver the message and if this caused the mailbox to reach 100%+, add a file
into the maibox say "username/Maildir/overquota". Interactions via
Dovecot IMAP/POP3 that lower the mailbox usage, for example the user popping, or
deleting mail from the mailbox would trigger Dovecot to unlink the file.
> Quota warning scripts can do that.
http://wiki2.dovecot.org/Quota/Configuration#Quota_warnings
>
>
They appear to trigger during maildelivers say via the LDA, however IMAP 
mailbox interactions (say deleting an email or copying an email) do not 
trigger them. I ended up having this patched into the quota plugin and 
works a treat.

On 31.8.2012, at 17.23, Dominic Malolepszy wrote:
> On 31/08/2012 11:40 PM, Timo Sirainen wrote:
>> On 23.8.2012, at 9.48, Dominic Malolepszy wrote:
>> 
>>> I am curious if Dovecot can add an empty file into a Maildir folder
as soon as a mailbox has exceeded 100% capacity, and later when it detects the
quota has fallen below 100% unlink the file. The idea is the Dovecot LDA would
deliver the message and if this caused the mailbox to reach 100%+, add a file
into the maibox say "username/Maildir/overquota". Interactions via
Dovecot IMAP/POP3 that lower the mailbox usage, for example the user popping, or
deleting mail from the mailbox would trigger Dovecot to unlink the file.
>> Quota warning scripts can do that.
http://wiki2.dovecot.org/Quota/Configuration#Quota_warnings
>> 
>> 
> They appear to trigger during maildelivers say via the LDA, however IMAP
mailbox interactions (say deleting an email or copying an email) do not trigger
them. I ended up having this patched into the quota plugin and works a treat.
The quota plugin, including quota warnings, works identically in LDA and IMAP.
So I wonder what your patch does.

Of course in IMAP a mail deletion is often a copy+mark as deleted with the
expunge happening sometimes later.