"Unscannable Max_Size" verdict given by Symantec Messaging Gateway Appliance

Products

• Messaging Gateway

Issue/Introduction

Under some circumstances, the Symantec Messaging Gateway (SMG) Appliance provides a random "Unscannable" verdict for emails with attachments with the "max_size" displayed under the "Details" section in the Message Audit Log (MAL).

The expected MAL communicate should look like below:

Verdict                      Filter Policy                                        Policy Group            Details 
Unscannable            unscannable: deliver normally         default                       max_size

Cause

Container limits under: Protocols -> SMTP -> Settings, under the "Scanning" tab are exceeded.  

The following is the default value under the "Container Limits" configuration section:  Maximum Individual file size when opened : 100MB  / Maximum Accumulated file size when opened : 200MB

Resolution

Change this setting to a higher value progressively till the error disappears.  

For example, change "100mb" to "200mb", then click on the "Save" button to save changes, and check the MAL to see if the error disappears.