Omar, FWIW, I don't run SAV on all email. I only use it on domains that are frequently forged like hotmail.com, yahoo.com, etc. That keeps me from DOS'ing my IMGate and still catches a reasonably high percentage of forgeries.
To help reduce SAV queries, I also whitelist VERP lists like returns.groups.yahoo.com. Otherwise, you are querying for every message from yahoogroups, etc. -NB
