How often does the Signature Spam Engine check for updates?

When does the GWAVA Signature Spam Engine get updates? How often does the GWAVA Signature Signature Spam Engine get updates? RE

The Signature Spam Engine does not get updates on a timed interval or using an update process or thread.  It works a little differently.  When GWAVA turns a message over to the Signature Spam Engine for scanning, the Signature Spam Engine will check it's local cache first to see if the message is listed.  If it is, the Signature Spam Engine returns to GWAVA that the message is listed and should be blocked.  If the message is not in the local cache, the Signature Spam Engine then queries the remote Signature Spam server (using port 80) to see if it has a definition.  If there is a definition, it is downloaded and added to the local cache.  In this way, the Signature Spam Engine is updated as needed rather than a scheduled definition download as a virus scanner would. 

This article was originally published in the GWAVA knowledgebase as article ID 1454.