Anti-Spam SMTP Proxy is a spam filter that sits on port 25 in front of your
regular SMTP server (sendmail, postfix, qmail, etc).
ASSP performs a number of configurable spam checks, and on detecting a spam
message, provides an immediate 5xx SMTP error code back to the client.
Non-spam messages are passed to your regular SMTP server for further
processing and delivery.
- a whitelist of known good senders
- Bayesian checks on message headers and contents
- recipient address validation using LDAP and RFC822 conformance
- relay denial(Only the first 15 lines of the commit message are shown above )