We send users regular emails with PDF attachments many times per day. (By sending as attachments, users can easily see the info using Verse on mobile devices). These emails are snapshots of business information, the emails do not need to be kept.
But users never bother deleting emails, so mailfiles and archives fill up with junk and we keep allocating more disk space on our servers!
Your mission Jim, should you decide to accept it, is to create the facility to send emails that auto delete themselves after a period of time/ days (......5 seconds is perhaps just a little too short).