Hey guys while I'm not familiar with force re-united or whichever sites are aggravating you, I do know you can add their email's to your spam list.
Block spam and other unwanted e-mail
http://googlesystem.********.com/200...-in-gmail.html
Blocking mail from certain senders - Gmail Help
If you are using anything like Outlook or Outlook express:
Add a name to the Blocked Senders List - Outlook - Microsoft Office
Just let me know if you have any trouble
-Adam