My webmail company (finally someone did it) put a bar in my webmail that shows the last time someone logged in and from what IP address. I don't understand why ALL email companies do not do this. Bravo.
Anyway, that's when I found out that someone at this IP address had logged into my email account, and wasn't me:
OrgName: Service Provider Corporation
Address: 442 Route 202-206 North
Address: # 485
NetRange: 126.96.36.199 - 188.8.131.52