Question: I got an email or a bounced email from my own email address. What is going on?
Answer: This is a common problem and question because spoofing or forging email addresses is very easy.
It is trivial to spoof, that is, forge, an email from any address. Viruses and spammers commonly spoof email addresses to hide their origins. What has most likely occurred is some computer on the Internet is infected with an email virus or other malware and sent email spoofed from your email address. When the email is rejected as spam or because it was sent to a defunct address, your email address gets the rejection.
The computer sending the spoofed or forged spam typically discovers your email address from a webpage, newsgroups, or a compromised computer that has your name in an document or address book.
The email rejection notices are not indicative of a problem with your email account or computer. Unfortunately, there is not much you can do except to delete the rejection notices.
You may want to visit Forged Spam Is Becoming A Plague (University of Michigan article) on this topic.
Please mail email@example.com if you have any further questions.