In the Symantec Messaging Gateway (SMG) UI, you receive the following message: "Your request cannot be completed within the specified timeout period. Increase the Symantec Security Response data transfer timeout limit on the Advanced Settings page and try again."
This is caused by a TCP/IP data transfer timeout between the Scanner/Control Center and Symantec.
Please contact support in order to change the timeout to a value that works for your environment if needed. If this is a one time error, it could potentially be ignored as it could be caused by temporary network slowness.