You are receiving bounced/undeliverable messages you haven't sent.
Several viruses on the Internet spread themselves through email by taking addresses in an infected machine's mail program and sending itself using those addresses. These masked messages, if rejected, are sent back to the false sender.
Therefore, you may receive returned messages to your account if someone got infected with the virus and has your email address.
- Change your password to prevent unauthorized access to your email account.
- Make certain you do not have a virus. Scan your computer using updated virus protection software.
- If you are not infected, simply delete the returned messages. Once the person's computer that is sending the virus gets repaired, you should no longer received the messages.