[pharno]

well, If you've got many many users registering each day, you will have many people writing a non-existing email. If you try to send it, you will get an email back saying that the user is not existing. So, instead of looking throu all the mails, you just dont ever look at it, and empty it every once in a while.

[AjJi]

Not if you add a "Reply-to" as the OP said.