Email filtering
The FortiGuard data centers monitor and update email databases of known spam sources. With FortiGuard Antispam enabled, the FortiGate unit verifies incoming email sender address and IPs against the database, and take the necessary action as defined within the antivirus profiles.
Spam source IP addresses can also be cached locally on the FortiGate unit, providing a quicker response time, while easing load on the FortiGuard servers, aiding in a quicker response time for less common email address requests.
By default, the antispam cache is enabled. The cache includes a time-to-live value, which is the amount of time an email address will stay in the cache before expiring. You can change this value to shorten or extend the time between 300 and 86400 seconds.
To modify the antispam filter cache size - web-based manager
1. Got to System > Config > FortiGuard.
2. Click the Expand Arrow for Web Filtering and Email Filtering Options.
3. Enter the TTL value for the antispam cache.
4. Select Apply.
To modify the web filter cache size - CLI
config system fortiguard
set antispam-cache-ttl <integer>
end
Further antispam filtering options can be configured to block, allow or quarantine, specific email addresses. These configurations are available through the Security Profiles > Antispam menu. For more information, see Security Profiles chapter of The Handbook.
See Also