Sendmail Sender Address Validator is a lightweight, fast, and reliable Sendmail milter that implements a real-time Sender email Address Verification technology. This can stop some kinds of spam with a spoofed sender's email address. It also implements real-time Recipient email Address Verification, which can be useful if your machine is a backup MX for the recipient's domains, or if your machine forwards all email messages as a relay host for your domains to another internal or external email servers. It is a light alternative for the spamilter, milter-sender, and milter-ahead milters.
