On Wed, Aug 31, 2022 at 09:56:49AM +0000, Frank Brendel wrote: > > You really should do something about that, build a table of over- > > quota recipients, and tempfail new mail for such users when briefly > > over quota, and ultimately reject if long-term over-quota. > > but is that possible with remote mailboxes?
If this is outbound mail to a remote domain, then it is much harder to know that the mailbox is full, you'd need to monitor the logs or the content of the deferred queue for recipients deferred with an extended status code of 4.2.2 <https://www.rfc-editor.org/rfc/rfc3463#section-3.3>, and then you could attempt to propagate this upstream, by tempfailing further traffic to the destination until the backlog of deferred mail to that recipient falls below a low water mark. But if you managed in less that $max_queue_lifetime to accumulate 250,000 messages to the same mailbox, something is wrong on the sender end. Whatever is generating the flood should be dealt with. -- Viktor.
