A common technique used by unscrupulous spammers is to use a stolen email address in the From header of their message. Or a made-up one that happens to match yours. So your address might go out to thousands of mailboxes as a spam sender. Many of these messages will bounce since spammers use email lists that are often computer generated and guess at what are likely real addresses to send to. It's common for spammers to guess potentially valid addresses by taking a common username and adding valid domains to it. For example, chances are there will be a " bob@ " at just about any provider's domain. They send out so many that a lot of these guesses will hit. But when they don't hit, some of the messages will bounce back to you, cluttering your mailbox with bounced messages you never sent in the first place.
This practice is fraudulent and illegal, and sometimes the culprits can be tracked down and stopped. But don't count on it, as these scam artists usually relay their messages through compromised computers to cover their tracks. You can find more information, and report these incidents here.
Usually if you wait a few days the spammer will move on to using some other victim's address and you will stop getting bombarded with these bounced messages. Unfortunately there isn't much you can do but wait.
We have some ideas about ways to block most of these "fake" bounces and only accept real bounces. Fake bounces can usually be identified because the original message didn't come from within EarthLink, but the spoofed address used by the spammer was an EarthLink address. We're looking into a method called BATV which can identify these fake bounces for us. Look for an update on this later.
Don't worry about the safety of your mailbox when this happens. Just because a spammer has used your address as the From line in their outgoing messages, does not in any way mean they have compromised your mailbox or have any access to your messages.