Try typing an email from an outside account and sending it to your address. Include in this message a few words that are generally in spam messages.
cialis, viagra, levitra
That should do it. Now... take a look at the message header when it arrives. You should see your words marked.
Don't go over board, because the system has an "autolearn" feature and if you send somethat that is absolutely spam you will be labeled a spammer.
The other thing you could do is just wait a few hours. You should certainly see some spam com through.... Or if you think you missed the spam, try looking at your procmail.log file. This is located in
/home/e-smith/files/users/<username>/procmail.log
and should have a list of the messages headers. Presumeably, some of these will be marked as spam.
Hope this helps.