Hi,
Take a look at the implementation guide Chapter 2, section "About using this product with other filtering products"
Here is a snapshot
The best practice to add antivirus protection to Symantec Brightmail Message
Filter software is to deploy the antivirus filtering feature. See “About filtering for viruses” on page 312.
....
If you choose to use a file system antivirus solution on the same computer as
this product, ensure that the antivirus solution does not scan the following
directories:
- The temporary directory
- The Symantec Brightmail Message Filter working file directory and all of its
subdirectories
- The IIS mail spool directories on Windows (when you use the default SMTP
virtual server)
- The MySQL directory