Sendmail Sender Address Validator 1.4.0

smf-sav is a lightweight, fast and reliable Sendmail milter that implements a real-time Sender e-Mail Address Verification technology. This technology can stop some kind of SPAM with a spoofed senders e-Mail address.
Also it implements a real-time Recipient e-Mail Address Verification technology. It can be useful if your machine is a backup MX for the recipients domain or if your machine forwards all e-Mail messages for your domain to another (presumably internal) e-Mail server. Sendmail Sender Address Validator is written in C.
Main features:
- friendly hosts/networks whitelist;
- SMTP AUTH support;
- strictly RFC-2821 compliant MX callback engine;
- tolerance against non RFC-2821 compliant e-Mail servers;
- blocking of e-Mail messages with a spoofed senders e-Mail address;
- recipients e-Mail address verification with an authoritative e-Mail store in gateway mode;
- slow down of recipients e-Mail address brute force attacks in gateway mode.
Enhancements:
- Whitelisting by a PTR (reverse DNS) record was implemented.
- Whitelisting by an envelope recipient email address was implemented.
- The option to ignore tempfailed results of SAV was implemented.
- The option to refuse email messages from systems that dont accept the null reverse-path <> was implemented.
- Tempfail and fail results TTL settings were segregated.
- Progressive slowdown of brute force attacks on a recipients email address was implemented.