[Dovecot] Postfix aliases with quota-status service

[Timo Sirainen]

On 6.8.2013, at 19.25, Thomas Leuxner <tlx at leuxner.net> wrote:

> * Timo Sirainen <tss at iki.fi> 2013.08.06 18:15:
> 
>>> Now the real problem along the road is the submitting server. If that server does not indicate the message size during handshake the pre-queue rejection simply can not work. 
>> 
>> quota_grace was meant to solve that. You'll allow the user to become a bit over quota.
> 
> What I meant is before the mail enters the Postfix queues. If the SIZE extension is not used during MAIL FROM by the remote server, then there's no way to reject an over-quota mail upfront, losing the benefit of the policy service.

The idea behind quota_grace is that the last mail would be allowed to take the user somewhat over quota (e.g. up to 109% quota usage). On the next mail delivery user is already over quota, so the size of the mail is irrelevant because a mail of any size will be rejected. The initial quota-status implementation didn't even support SIZE extension since I didn't remember it existed.