When Symantec Mail Security for Microsoft Exchange (SMSMSE) is started and content filtering is enabled, certain AutoCAD files with the .dwg extension are left in the temp folder (default location C:\Program Files (x86)\Symantec\SMSMSE\7.0\Server\temp) and not deleted properly, resulting in ever increasing disk space usage and eventually filling all available free space on the drive.
A content filtering sub component is locking this particular type of file in use at the time the scanning process attempts to delete it, resulting in the file never leaving the folder automatically.
Symantec is aware of this issue and will update this document when a solution becomes available. It is not necessary to log a support case on this issue. Please subscribe to this article to be notified of any updates.
Workaround
Disable content filtering "attachment content" inspection of AutoCAD files. Note that this will prevent SMSMSE from identifying content filtering violations within "Attachment content" of AutoCAD files, but will not effect other file formats.
To disable content filtering "attachment content" inspection of AutoCAD files:
Once these steps are completed, these AutoCAD files will no longer build up in the temp directory.