[Dovecot] Dovecot or postfix Quota
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
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!
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
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
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
participants (3)
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Adrián Ribao Martínez
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Alexander Prinsier
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Johannes Berg