We looked at the appliance model as well (specifically Barricuda). We decided against it b/c the configuration of LDAP and if the link breaks for some reason (i.e., the appliance goes down or Domino server goes down) then it seemed both needed to be reset. Plus this seems to add an additional query to the Gateway Server (or any other server). We went with the native Domino solution, and chose Spam Sifter from INVCS (ex-Iris guys built it). Yes, I sound like a commercial only because it’s great. It worked within 10 minutes after installing it. Our spam count went down from 80,000 spam messages a day to around 40-50 for all of our users.
Anyway, I think they are offering a special 6 months trial. Check them out: