Symantec Premium AntiSpam provides continuous updates to the premium antispam filters to ensure that your Exchange server has the most current spam detection filters. Updates to the premium antispam service are handled automatically through the Symantec Premium AntiSpam service and not through LiveUpdate.

You must have an active Internet connection and permit outbound secure HTTP traffic through your firewall (port 443). Manually register the service if your connection uses an HTTP proxy. After Symantec Premium AntiSpam is registered and enabled, spam rules are continually downloaded from Symantec. Mail Security checks for updates every minute and receives new rule sets every 10 - 15 minutes.

See About registering Symantec Premium AntiSpam through an ISA server

See Configuring your proxy server to download spam definition updates