Mature

The rlytest utility tests a host to determine whether it will relay third-party email. It will try to relay an email message to yourself through that host. A host that allows third-party relay is subject to attack by Internet vandals, and frequently is hijacked by spammers to relay massive amounts of junk email. A host that allows third-party relay should be immediately secured, disconnected, or shunned as a menace to the Internet.

pxytest is a command line utility to test a host for open proxies that are vulnerable to spammer abuse. It is written in perl.

Unsecured proxies can be a conduit of spam. This is a particularly vexing problem, because open proxies, unlike open mail relays, hide the origin of the spam, making it impossible to trace. This utility
tests a host to see if it is vulnerable to such abuse.

Some organizations, such as the MAPS RBL and MAPS DUL, publish lists that identify potential sources of spam and email abuse. The blq utility is a Perl script that queries one or more of these lists to determine if a particular host is listed.

It works something like this ...