SecurityGateway's Spam Engine can automatically update its Heuristic rules (if new rules are available). This article outlines how to configure the interval at which SecurityGateway checks for these updates.
Log into SecurityGateway as a global administrator
Click Security
Locate the 'Anti-Spam' section
Click Heuristics and Bayesian
On the right-hand pane locate the 'Location (All Domains)' section
click the link titled Click here to configure SGSpamD
Select either Check for heuristic rule updates at midnight each night or Check for heuristic rule updates once every __ hours and enter the interval at which you wish the check to occur.
Click Save and Close.