Help! Am I hacked? What do I do?
Worry not, this is just a common and simple ploy that spammers use to send you email called "spoofing". It does not mean your account has been hacked and it does not mean that anything is wrong. It simply means that the spammer faked the return address when they sent it to the recipient, which is extremely easy to do.
Just delete the email, or move it to your isSpam folder, just like you do with any other spam, and then go about your business.