Antivirus Exclusion
After installation has completed and prior to building the first relationship, create an exclusion in your antivirus scanning package for the Add2Exchange installation directory. This is the directory you chose Typically this is C:\Program Files\OpenDoor Software®\Add2Exchange or C:\Program Files (x86)\OpenDoor Software®\Add2Exchange for Server 2003 and Server 2003 x64 respectively.
The reason for adding this exception is that the directory where Add2Exchange is installed both hosts the Add2Exchange database as well as provides a temporary storage point for the replication of attachments on items in Exchange. Antivirus scanning on these files is both unnecessary as well as performance prohibitive to synchronization.
See the documentation included with your antivirus product on how to add exclusions for directories.