I believe that someone else has asked for this already but I would like to queue up for this as well.
What would be nice is a TRASH folder similar to the SPAM folder to which we could move e-mails that are not spam but are not worth cluttering up our database with. The items in the TRASH folder could then be deleted occasionally by an Admin.
For example, we sometimes find it necessary to send test emails to test one of our accounts that does not seem to be responding. It would be nice to just be able to junk these emails rather than add them to the database. Other stuff comes in as well that would be nice to just get rid of. But only an Admin should have the power to actually delete the trash.