[Dovecot] Dovecot handling of over quota messages

[Andrzej Adam Filip]

Timo Sirainen <tss at iki.fi> wrote:

> On Sat, 2009-01-17 at 21:02 +0100, Andrzej Adam Filip wrote:
>> Are there any plans to allow MTA check recipient over quota status?
>
> Not really. Perhaps once LMTP server is implemented, since it pretty
> much requires the same functionality.
>
>> Sendmail support simple "socket map" protocol that can be used for 
>> such queries.
>
> Wasn't the socket map also (mainly?) used for verifying if a user
> exists? That I have been planning on implementing some day (for last 5
> years or so).

AFAIR Socket map was originally intended to allow "stable sendmail code"
integration of  "multitude" of databases (mysql,oracle,postgress,...).

Currently it is used to ask Cyrus IMAP if user (recipient) exists.
---------------------------------------------------------------------
It may be used to:
1a) ask mailbox server with virtual domain (e.g. dovecot) which domain it
    wants/handles at sendmail daemon startup
1b) reject messages to overquota mailboxes in reply to "RCPT TO:" (4??/5???)
    [Cyrus IMAP does not try to detect "this message" will cross quota]
1c) implement aliases 
    It should allow "per virtual domain" email administrators
    implemented in dovecot.
1d) allow users to specify "at 'RCPT TO:'" sieve scripts

All the above (1*) requires only modifications in sendmail.cf 
at "sendmail side".
---------------------------------------------------------------------
After modification of sendmail source code socket map may be used to
pass to sendmail information about virtual users (uid,gid,$HOME).

It should allow:
2a) supporting .forward files *for virtual users* (e.g. ~/.forward.user)
2b) making sendmail execute deliver program with uid and gid of virtual
    user
---------------------------------------------------------------------
Consider also implementing support for (simple) saslauth protocol
together with socket map => it will allow sendmail (without dovecot sasl
support) to use/check passwords stored by dovecot in SMTP AUTH.

-- 
[pl>en: Andrew] Andrzej Adam Filip : anfi at onet.eu
This generation doesn't have emotional baggage.  We have emotional moving vans.
  -- Bruce Feirstein