It is illegal in Maryland:
http://www.spamlaws.com/state/md.html
However, it is a civil issue, not a criminal one. Therefore, there is no one to report it to. If you can locate the culprit, you can drag him to small claims court and get $500.
Chances are that you aren't going to find him.
Certain types of SPAMMING are now criminal offenses in Virginia.
What is probably going to happen in the near future is that the Congress is going to get legislation through that basically makes it illegal - on a federal level - to send commercial email with false headers, deceptive subject lines and content, via someone else's server w/o their permission (open relays).
However, they are going to open the floodgates for "legitimate" companies to SPAM you legally. By definition, SPAM is any UNSOLICITED commercial email. Congress is going to ensure that there is an OPT-OUT system as opposed to an OPT-IN system as there should be. Then the "legitimate" companies are going to find all kinds of loopholes to make it difficult to get off their lists, i.e. well you opted out of mailings for our toothbrush department - this mail came from our toothpaste group and is perfectly legit IAW U.S.C. blah-blah. I have already received quite a bit of SPAM directly from IBM at a Yahoo address I have-despite using their removal link.