[Hnrobert42]

>smart spammer

I am sure there are plenty of smart spammers, but it also seems like a lot of spam comes from folks using scripts and email lists they use without fully understanding. It appears SpamAssassin would help with those operations.

[bombcar]

I'm starting to think the smart spammers are the ones selling worthless spam tools to the dumb spammers, because so much spam is entirely unactionable.

[brightball]

Part of the smart spammer approach is to condition people to what spam looks like, so you're more likely to let through the ones they really care about.