SpamCop Problem

I have attempted to setup SpamCop for use with Squirrel Mail, but something isn’t working properly. I created an account with SpamCop that I can access without incident. When I attempt to submit spam from Squirrel Mail, it always fails and provides the note “No userid found, sorry”. Apparently, my userid is not recorded properly. When I attempt to enter my userid into Squirrel Mail, it always truncates the entered value starting with the ampersand “@”. For example, would be recorded simply as abc. Any idea how to setup SpamCop within Squirrel Mail?