The spasm perl anti-spam milter is a spam filter for modern sendmail versions with libmilter support. Its current features include logging and quarantining of rejected spam, fully virtualized settings for domains, individual whitelists and blacklists, and over two dozen filters that can be set individually, on a per-domain or per-email address basis, including local (system) blacklist, rDNS resolution, HELO/EHLO verification, envelope sender address verification, numerous DNS-based lists, whitelist-only mode, and auto-blacklisting via spamtrap addresses.
