If you remember my problems of a week ago with a "zero hour virus" (virus that is so new that it hasn't been added to Dat files) version of Mydoom, you will recall my lament that neither McAfee's engine that Postini uses nor our own Symantec caught the new Mydoom.AZ variant.
Well Postini just announced today that they are adding a new layer of virus protection in addition to their existing McAfee protection:
"Virus Blocking: Authentium Antivirus Added as Second Virus Engine
Enterprise Edition now provides better virus protection with the addition of the Authentium Antivirus engine. For an added level of inspection, Authentium scans all inbound emails which are determined to be clean by the current McAfee Antivirus engine. The strengths of Authentium Antivirus are its heuristic virus scanning engine, and ability to detect viruses in files that are compressed and encrypted. Authentium provides both weekly antivirus definition file updates and urgent updates. Perimeter Manager polls Authentium for antivirus definition file updates every minute to ensure timely protection.
The addition of Authentium Antivirus gives Enterprise Edition two sources for antivirus definition file updates and two heuristic techniques for catching viruses. This augments Postini's ability to protect you from known viruses as well as zero-hour threats (new viruses that have not yet been included in antivirus definition files).
Authentium Antivirus protection will be rolled out to groups of customers over the month of March. We will send a notification when the deployment to all customers is completed. At this time, we cannot notify you individually when you have been upgraded to Release 5.4. However, you do not need to make any changes or configuration settings to enable Authentium Antivirus. We thank you for your patience throughout this process."
That should take care of the issue of new viruses getting through at least from the email vector standpoint.
If spam and virus laden emails are a problem for your organization, why aren't you using Postini or some other web based solution? I don't quite understand why anyone would use Barracuda (a hardware spam filter that sits inside your network, allowing spam traffic to use up your bandwidth) as their first line of spam defense.