Hash Buster strings
Not seen very frequently nowadays, but these were a staple of spams during 2002-2003 or so.
they'd look like this:
| No Format |
|---|
Blah blah spam text blah http://www.example.com/link/ blah blah oaynxwhgarpsottqxiloxlrwxp |
the "oaynxwhgarpsottqxiloxlrwxp" block of gibberish at the end is the hash buster.