Limit emails kept on server per account
The IO's on forgotten emails or catch emails can get out of control and damage the server.
An amazing option is to set an overall limit of emails allowed on the server for a given email address.
For example firstname.lastname@example.org would have a 10k email limit. Just like sending limits or space limits this overall email limit would avoid rogue email addresses from using hundreds of thousands inodes and degrading the performance of the server.
It would in the in the WHM and not seen by the users. In the email limit section you could search emails to limit one by one or have the ability to batch several emails to a limit. It would also have a default limit that would be set for each new account on the server.
Or you could just add an overall email limit per package in the create and manage packages section. This might be useful for offering an upgrade to customers.
I just think it would need to be set per account without cvhanging the package as well.