How does Barracuda filter spam/viruses?
There are many methods typically used today to combat email spam and viruses and Barracuda combines no less than 10 different methods to identify and process email right out of the box. Barracuda combines rules and definitions dealing with spam and viruses which are contained in its own databases (updated to the Barracuda as often as hourly) and externally available block lists to identify undesirable email. Here is a quick list and description of each method in the order that the Barracuda Spam Firewall applies them to an incoming message. -Denial of Service and Security Protection Analysis. This is an initial analysis of the smtp connection being used to transfer email in order to insure that some basic indicators of legitimate email are observed and some obvious indicators of potential spam are picked up on. This entails such things as timing out an smtp session, limiting the number of messages per an smtp session, insuring domains are fully qualified, detecting and rejecting email
