mxallowd is a daemon for Linux Netfilter (using libnetfilter-queue) and BSD pf (using pflog) which implements a slightly improved nolisting mechanism. It requires your name server to be configured to return two MX IP addresses, and the one with higher priority must not run a mail server on port 25. mxallowd blocks attempts to connect to the mail server unless the sender tries to connect to the first mail server before the second. Since most spammers will attempt direct connections to each mail server, they will be blocked.
|Tags||Communications Email Filters Networking Firewalls Internet|
|Operating Systems||POSIX Linux BSD OpenBSD NetBSD|
Release Notes: The program no longer crashes when resolving fails.
Release Notes: mxallowd is now correctly started in the background. The pidfile is written correctly (using O_TRUNC).
Release Notes: This release creates a correct /var/run/mxallowd.pid to allow it to be started with start-stop-daemon while checking for the return code correctly.
Release Notes: Besides fixing a bug in the IPv6 implementation, this release adds support for NetBSD and OpenBSD (probably FreeBSD as well, but this has not been tested) using pflog.
Release Notes: mxallowd now supports IPv6.