Re: Handling Over Quota Bounces

Hi Matt,

At SFU we run a script that automatically increases quota for staff and faculty who are over 90% of their mailbox usage, so they should never run up against quota issues. At first we did it on request, then we pushed it out to departmental techs to be able to do, then we just decided to automate it since we never refuse it. Students don't get increases, so they're the only ones who can run up against quota issues. As such, we typically only have a couple of dozen messages deferred at any given time.

I'm somewhat undecided on fast-bouncing over-quota messages. I know some sites do it, but I tend to favour letting it queue for awhile. Some (many?) senders don't pay attention to bounce messages, so they may not notice it didn't get delivered, and if it fast-bounces, there's no opportunity for the receiver to fix their over-quota condition and receive the messages that would potentially have been waiting for them.

We have almost 10,000 messages in our deferred queues on our Zimbra MTAs. Out of those only ten are deferred for any reason other than "over quota". So nearly 100% of our deferred queue is "over quota" deferrals.

The current default behavior on an over quota message is to defer and retry the mail for 5 days and then let the sender know their recipient was over quota. I see I can eliminate this default behavior and bounce "over quota" emails immediately with this...

zmprov gacf zimbraLmtpPermanentFailureWhenOverQuota

Five days is a long time for a sender to think their message was delivered when it actually was not. They never know until they get the bounce on the 5th day. I think the conventional wisdom these days is to fail fast....so if there is a problem the sender should know immediately. And of course a lot of it just junk marketing, mailing lists, and bouncing bounces, etc...

It seems we have a lot of accounts that go over quota during the summer because the customer doesn't check their email regularly, part of the problem of being an EDU.

How are other schools handling this? What seems to be standard practice?

Thanks,
Matt Mencel
Western Illinois University

Steve Hillman IT Architect
hillman@sfu.ca IT Services
778-782-3960 Simon Fraser University