Every now and then, I have a look inside /var/mail and find a few emails that bounced. They are always some automated mails sent out by a CMS (in this case Wordpress) i.e. after a new user signed up that bounced, i.e. the user signed up with a wrong email. They are all sent via phpmail() and the sender is something like "webxxx@myserver" There are very few, I just checked and found 3 from within the last 3 months. I was just wondering what could have gone wrong and why they are ending up in that folder instead of in the proper vmail folders?