find out who sent the email to me
Elden has a point. Opening messages from people you don't know can be hazardous to your computer. Sometimes, you need to read them, however.
If a message is spam, simply report it to AOL and let them figure out who sent it.
If you really want to try to figure it out yourself, the information is in the message headers. Headers usually are not displayed so you'll have to make them show up (how to do that depends on your email software). Read them closely to see where the message came from.