On Fri, 4 Mar 2005, Mark Shewmaker wrote:
The reason I ask is because of:
$ host -t txt advanta.com
advanta.com text "v=spf1 mx ptr mx:18.104.22.168 mx:22.214.171.124 ~all"
The strings after the mx mechanism aren't IP addresses, they are
domain names. They both result in NX_DOMAIN because there
is (currently) no top level domain of ".100" or ".108".
The above SPF record in syntactically correct and has a well
defined meaning. The last two mx mechanisms will never match
until there is a top level domain of ".100" or ".108".
Given that the two ip's listed are their mx hosts, it looks like they
could just as well use "v=spf1 mx ptr ~all"
or even "v=spf1 ip4:126.96.36.199 ip4:188.8.131.52 ptr ~all".
Having finished being pedantic, I agree that they almost certainly did not mean
what they say in their SPF record. Since any IP that would match what we think
they really meant by the last two mx mechs would have already matched the first
mx mech, their mistake isn't really hurting anything.
Stuart D. Gathman <stuart(_at_)bmsi(_dot_)com>
Business Management Systems Inc. Phone: 703 591-0911 Fax: 703 591-6154
"Confutatis maledictis, flamis acribus addictis" - background song for
a Microsoft sponsored "Where do you want to go from here?" commercial.