Not sure if this is a bug or not (subjective), so placing here for now.

Issue:
-when a mailbox approaches their quota limit they will receive periodic warnings until it actually exceeds their limit, then nothing

Example:
I have a domain on our server with over 300 accounts, each with a 50MB limit, and about 10% are full all the time (abandoned or not actively in use), and no additional alerts are sent regarding them being full. This makes it a challenge to quickly identify wasted space/dead accounts and causes unnecessary message bouncing, etc.

Scenario:
-user is at 9/10 MB limit they get a warning (as does the domain default account)
-user hits 10/10 MB limit a final warning (usually) gets sent
-if nothing is done, no additional warnings are sent (based on my observations anyway)

Suggestions:
-Daily digest type report should be sent to the domain default account advising the administrator of all mailboxes exceeding the globally configured warning levels (ie: 90% and above). Report should merely list the offending mailboxes and their usage values (same as the current messages).