This would also be useful for me.

A use case is a client who has an external email address they use, such as an AOL, Hotmail, or GMail account that they want all their email forwarded to. However, as these providers are known to discard some messages or unnecessarily hide them, the user wants the ability, for a limited time, to check to see if a message got "lost" in transfer from the PLESK server to their chosen email host.

This is also useful for a "catch-all" or "junk" email address that you want to be able to receive messages just in case, but don't want to have to manage unless you have need to look for something.

Being able to set an automatically delete messages older than... on a given email account would keep these scenarios (or possibly others) from filling the hard drive on a server with messages that aren't going to be checked.

Hello,

What are the desired usage scenario and business cases of your feature request?
It would be needed to have a no-reply@example.com email account and to don't have the necesity to delete the emails at the inbox.

Not sure how can this be implemented but mailboxes getting full from messages(spam) that gmail does not download

It would be nice if there is a way to auto clean undownloaded messages after a while

Have account with over 60,000 emails going back over 2 years in location.
/var/qmail/mailnames/######/######/Maildir/cur

With suggested option subscription owner could configure regular cleanup themselves - assume they would be in control of downloading emails to mail client.

The other alternative is for the Plesk admin to have a 6 month old mail cleanup script - bit heavy handed, subscription owner has no control.

Add to email address mailbox configuration - after mailbox size.

For those who have email forwarded but use an outgoing emailbox for their domain name, this would be a great housekeeping tool...a setting that would delete email messages that were X days old or older.