You’re a Bayesian Filter!
A Bayesian filter, such as POPFile, will quietly discard any type of mail you don’t want to read. You train the program by correcting its “junk” or “not junk” guesses on individual messages. Over time, the programs statistical accuracy improves dramatically, to the point where it can be trusted to file junk mail into a separate folder.
No algorithm is perfect, though. When new spam styles arrive, the program needs retraining. You should also check your junk-mail folder periodically for false positives, lest you miss your wife’s Valentine’s Day message from the airport kiosk. (True story.)
In a past life you might have been:
A Collaborative filter
A Whitelist program
No filter at all