Dovecot or postfix Quota

Previous Topic Next Topic
 
classic Classic list List threaded Threaded
5 messages Options
Reply | Threaded
Open this post in threaded view
|

Dovecot or postfix Quota

Antares
Hello,
I'm a bit confused with the dovecot quota support. What is it for?
I thought postfix should be the one managing the quota. If I set up a quota in
dovecot, does dovecot keep the messages size under certain limit?
What happen when you reach the quota limit?
What's the difference between postfix quotas and dovecot quota?
I'm confused about this.

Thank you!
--
Adrián Ribao Martínez

signature.asc (196 bytes) Download Attachment
Reply | Threaded
Open this post in threaded view
|

Re: Dovecot or postfix Quota

Alexander Prinsier-2
Hello,

First of all, postfix doesn't support quota's by default. There is the
quota patch of course. But there is a reason that it isn't included by
default. (but I'm not sure what the exact reason is, if it's not the one
below).

Secondly, how do you define the quota of a mailbox? There are many ways
to do that. (Filesystem quota's, Maildir++ quota, and probably other
ways). Do you think it's the mail 'routing' system's job to know all
these different implementations?

Instead I think it's a cleaner (and more logical) way to let the mail
delivery agent take care of this, hence by deliver from dovecot.

Alexander

Adrián Ribao Martínez wrote:
> Hello,
> I'm a bit confused with the dovecot quota support. What is it for?
> I thought postfix should be the one managing the quota. If I set up a quota in
> dovecot, does dovecot keep the messages size under certain limit?
> What happen when you reach the quota limit?
> What's the difference between postfix quotas and dovecot quota?
> I'm confused about this.
>
> Thank you!

Reply | Threaded
Open this post in threaded view
|

Re: Dovecot or postfix Quota

Johannes Berg

> Instead I think it's a cleaner (and more logical) way to let the mail
> delivery agent take care of this, hence by deliver from dovecot.

Any self-respecting mail administrator should avoid sending bounces like
the plague, hence the need to check whatever you possibly can during the
smtp transaction. Quota certainly ought to be checkable, and if you then
accept a few mails too many due to race conditions I guess you don't
really care.

johannes

signature.asc (845 bytes) Download Attachment
Reply | Threaded
Open this post in threaded view
|

Re: Dovecot or postfix Quota

Alexander Prinsier-2
Johannes Berg wrote:
>> Instead I think it's a cleaner (and more logical) way to let the mail
>> delivery agent take care of this, hence by deliver from dovecot.
>
> Any self-respecting mail administrator should avoid sending bounces like
> the plague, hence the need to check whatever you possibly can during the
> smtp transaction. Quota certainly ought to be checkable, and if you then
> accept a few mails too many due to race conditions I guess you don't
> really care.

I agree that bounces should be minimized. Still the most logical
solution would be that the MTA asks the MDA about the quota status.

However I don't know any way to let postfix ask the MDA about quota
status. Even bypassing the MDA, do you know of any software that plugs
into postfix that can check filesystem quota's?

I need to use filesystem quota's because I also need to set a group
quota (which is not only used for email, also for other files).

Alexander
Reply | Threaded
Open this post in threaded view
|

Re: Dovecot or postfix Quota

Johannes Berg

> I agree that bounces should be minimized. Still the most logical
> solution would be that the MTA asks the MDA about the quota status.

Yes, that could be doable. Although, dovecot's LDA doesn't actually
support this. And then there's the issue of race conditions: You ask it,
accept the mail, and when you go to deliver it the user has saved gotten
another mail in the meantime. At that point, you probably should just
accept it anyway, but if the LDA checks the quota again you'll end up
with a bounce message...

> However I don't know any way to let postfix ask the MDA about quota
> status. Even bypassing the MDA, do you know of any software that plugs
> into postfix that can check filesystem quota's?

Sorry, I know nothing about postfix at all. And even for exim (which I
use) I couldn't tell you off-hand, but it's most likely possible to do.

johannes

signature.asc (845 bytes) Download Attachment