More on Anti-Spam/Anti-Virus Solutions

Thanks to everyone who has responded regarding the Barracuda Network Spam Firewall. They look like very low cost but very powerful boxes. We are in the process of choosing an anti-spam/anti-virus solution for our current email enviroment (Sendmail Pro on RH9 Enterprise). One of the vendors that caught our eye was Sophos, and their PureMessage product http://www.sophos.com/products/pm/. However, I have not read much regarding integration issues with PM into an existing Sendmail Pro enviroment. Anyone have any success/horror stories on this? Thanks, Tom Claydon