rfci lists so many people that one can't rely on (they liste yahoo, aol, hotmail, ....) except for a personal site (or a company where you can enforce your rules). A fashist approach might (seem to) work, but it'll never solve the real problems.
/Agree.. I use most of RFCI as an informational indication that the domain doesn't handle things the normal or proper way.
The only RFCI list I find to have any chance of usability is bogusmx. Although even that is slightly over-picky for real world applicability. It's unfortunate that RFCI doesn't differentiate between those with a MX record pointing to bogus IP space or is unresolvable, and those which are merely misconfigured by a well meaning but undereducated (read: just barely got a MCSE) IT staffer and point to a CNAME. While returning a MX record that returns a CNAME is a RFC violation, and may cause trouble for mail delivery, it's hardly worth blacklisting someone over.
ipwhois performed very well in the SA tests, but it doesn't even have a published listing criteria anymore, thus I can't consider it trustworthy and wonder if it's maintained or not. (see for yourself :http://www.rfc-ignorant.org )
RFCI is not nearly as Fascist as spews, but IMHO it's lack of differentiation between serious deception and minor misconfiguration limits it's real-world usability. While some parts of RFCI did very well in the pre 3.0 mass-checks, my own experience with them has been substantially less impressive. This is probably heavily biased by the number of small businesses my company works with. Small companies are the most likely to have a single IT guy running the show, and those usually have good knowledge of windows, and very poor knowledge of IP networking. They're the most prone to have minor mistakes, typos, etc.
(Sorry Paul, I know you work hard to contribute to RFCI, and all the information the publish is correct, it's just becoming less and less useful in spam fighting for me.)
