- Local Antispoofing and Anti-Relay
- Honeypot filtering
- SPF/MX record matching
- DNS-based blackhole lists
- Custom rules based on envelope and header fields and email content
Anti-Spam
StoneGate FW/VPN contains a
built-in Anti-Spam feature that is designed especially for small and medium sized customers or
remote sites having their own email domain and inhouse SMTP email server.
The fundamental idea of StoneGate Anti-Spam is that each incoming SMTP e-mail is assigned a score to determine the likelihood of its being spam. The user can alter the score thresholds 1) after which the firewall will add SPAM prefix to the message subject and 2) after which the firewall will reject the message.
The system uses many different functions and algorithms for spam detection. In addition to score based spam detection it is possible to mark email as spam, discard, reject, blacklist and graylist based on any envelope field, header field or email payload. The values can be input either as plain text or regular expressions. If none of these custom rules matches the received email message, then the scoring is used to make the decision whether the message is allowed, blocked or marked as spam.
