We have a scheduled task running weekly to archive the mail files (compact -A).
I am seeing servers with specific mail files starting to hang on processing. These tasks are apparently continuing for more than one week, as multiple tasks are showing hung on specific mail files.
It appears that the only way to clear these running compact tasks is to reboot the server.
When I saw the first instance of this, it was on a 6 GB mail file and thought it might be a size issue. However, it is now occurring on a 200 MB mail file as well.
I am uncertain if this means mail files after these users are not being archived, but I believe that to be the case.