Thursday, February 28, 2008

Don't Panic

A couple of weeks ago, I talked a little about how spammers use your own e-mail addresses as a way to trick spam filters. And though it was implied, I forgot to talk about one more issue that this creates: the fake bounce messages.

Many years ago, when the Internet was made up of nothing but nice people, the idea of spam and viruses were never a consideration. And the network was not always reliable. E-mail addresses changed or there were problems. Someone got the idea that one solution would be the equivalent of a "return-to-sender" in postal mail. So they set up the bounce message. It would tell the sender that the message didn't reach a recipient, and give a reason (no such address, mailbox full, etc.). This was useful for troubleshooting and as general information.

But viruses and later spammers eventually learned to "spoof" an e-mail address. This means to put a fake e-mail in the "From:" field of a message. This is usually chosen at random from the list of addresses to be spammed. The result is that you can get a bounce message saying the message is undeliverable -- even when you haven't sent a message.

This doesn't mean you have a virus. It's just that your e-mail address won the (un)lucky drawing. You can safely ignore the message. You may get several of them for a few days and then not see any more.

There's no real prevention. The reduce these (and for other reasons -- spammers use the bounce messages to determine what e-mails addresses are good ones), most system administrators turn off this feature. But there are always a few who don't bother or who aren't up to date with best practices, so the messages will be with us for a long time. Just delete the message and move on.