Large uptake in spam?

[Rob Poe]

I've noticed a large uptake in the amount of spam my gateways are seeing.

Of course, it's causing a higher than normal load on the servers, and people are complaining because we're getting SA timeouts due to the load.

Do people here use / recommend setting up Sendmail to reject based on no valid reverse DNS?

Milter-SAV ?

What free RBL's are people using?  The ones I've seen are "Use this lightly" and if you don't .. you get blacklisted from them ..

What else do you recommend?

I'm using Sendmail / SMF-Grey / SA / MailScanner

Server is P4 1.9 2gigs mirrored IDE hard drives..