Originally posted by: Shooters
There's not a whole lot you can do by yourself, but give this a shot.
Take a look at the e-mail headers. In Outlook go to View ---> Options; in Outlook Express it's Properties ---> Details. Scroll down in the headers section until you see the "Received From:" line which will have an IP address. If you see multiple "Received From:" lines then most likely the bottom one is the originating server address. Once you get the IP address go
here and enter the address. This should return the person(s) that the IP address is registered to, most likely an ISP, with phone numbers and probably information on how to report e-mail abuse.
That's about as far as you can get by yourself. However, if one of the ISP's users is indeed hacking into you and your girlfriend's e-mails then give them a call or send a message to their e-mail abuse address, and they can probably track down the culprit.