Missing spam

Spamsieve is catching almost everything on a regular basis except for a few errant emails - usually having to do with some drug. I have tried entering in the blocklist rules: Subject -> contains -> V1agra (for instance) but spam still slips through with that in the subject. Does the entire subject have to match or can spamsieve find single words in the subject - and if it can, why is it missing these few but regular spams?

Blocklist rules can match single words in the subject. If you had a blocklist rule that should have matched a message, the rule was enabled, and the message was not caught, then there might be a setup problem such that SpamSieve was not asked to filter that message. Another possibility is that one of SpamSieve’s filters above the blocklist decided that the message was good. You’d be able to see this in the log.