Some of my spam seems to originate from my email address. Is my account infected?

Probably not.

Most spam is sent with a fake sender name and/or address. This is done to add a potential sense of credibility or legitimacy to whatever message is being sent. This process called e-mail spoofing, where the sender's address is forged to appear as though it came from an innocent party. In e-mail spoofing, the sender manually constructs the e-mail header and chooses which information (your e-mail address as the sender, for example) to include. Wondering how they got your address to begin with? There may be a number of ways. One possibility is that someone you know, or have had e-mail contact with, has had their computer or account compromised, and it is now being used to run software to send mass emails. This software can go through a user's contact list and send spam all over the world using random addresses from the contacts list (including yours) in the from field of the spam messages.

Messages that come to you "from" you are generally for scammers to avoid email filters. Scammers know that you most likely will not have a rule blocking emails that you send yourself, so by forging the from address their aim is to slide through undetected. An intrepid user might notice that often the mail server itself is illegitimate; this is a surefire way to tell that the message is fake.

If there is an email for which you are particularly concerned, or if you are unsure of its source, send an email to security@umbc.edu and the Security Group will take a look.