I'm looking for a good spam filtering service for a small business (< 25 people).  I'm looking for a solution similar to Postini, where I set my MX records to route mail for my domain to the spam service, they do the filtering and then send the mail to the destination.Postini is certainly inexpensive enough our technical folks believe the configuration options and user interface are complex.What alternatives exist that might be more simple?
What are alternatives to Postini for spam filtering?
email;spam prevention;postini
Leo Laporte gushes about MailRoute.