I made up a new way of blocking spam: MTX records

[darxus]

http://www.chaosreigns.com/mtx/

MTX records are just DNS A records on your DNS server stating that an IP is a legitimate mail transmitter.

There is a SpamAssassin plugin for it on that page.

Comments

[frobzwiththingz.livejournal.com]

a) How is this *functionally* different, as opposed to *syntactically* different, from an SPF record?

b) I have SPF records for all of my domains. Have had them for more than 5 years now. As of this writing, not enough of the rest of the world has also done it, making it still something i can't really use as a decent wheat/chaff separator. Sigh. Even if you reply with something I'm not seeing in (a), I don't hold much hope.

[darxus.livejournal.com]

a) See my previous comment for functional difference (forwarding breakage).

b) I tried to address this in the "Implementation Sequence" section. I think it's useful for whitelisting now. And I am hopeful that people will adopt it for that reason - reducing false positives. Meanwhile I am also using it to increase the spamminess score of email without an MTX record to catch more spam. This requires a willingness to cause a small number of false positives - which I have largely because I have SpamAssassin configured to run during SMTP delivery so I can reject spams, causing un-forged senders to get an error message without causing backscatter.