Since upgrading to SmarterMail Enterprise Edition Version 15.2.6039, certain mailbox owners began complaining about missing mail from their "Sent Items" folder. There were 3 inactive and 2 active folder auto-clean rules set globally, with domains and user typically allowed to override. The two active rules were set to clean the "Deleted Items" folder and the "Junk E-Mail" folder. One of the inactive rules cleaned "Sent Items" down to a certain size. Of the users that complained, none of them showed additional auto-clean rules for the domain or the individual mailboxes.
It wasn't until I turned up the detail level for logging auto-clean folders that I got the first clue of what was actually happening. We were restoring mail back to customers, only to see the messages disappear again. The logs correlated times with "Removed XXXX email(s) from folder sent items" for the mailboxes in question.
I have since removed the inactive rules, and for another measure, stopped allowing domains to override the settings. What is going on here?