On 5/5/2005 9:39 AM, Dan Barker wrote: > I can't find any doc on PTR rules. Specifically, I'd like to make my > SpamAssassin 3.0.1 score if there is no PTR record for the first > "foreign" IP in the "Received by" chain. > > This can't be difficult, but I've scanned the doc to the best of my > ability (my best may not be particularly good<g>) and come up empty.
http://www.rulesemporium.com/forums/showthread.php?s=&threadid=105 has a collection of tests that look for this and some other SMTP "problem" cases, using the X-Spam-Relays-Untrusted psuedo-header that spamassasin generates during its testing. If you don't want to use the meta ruleset, the specific sub-rule you want from there is __L_RCVD_HOST_NO_RDNS: # # This rule looks at the top 'rdns' field of the X-Spam-Relays-Untrusted # psuedo-header, and if the field value is null, it assumes that the # server was unable to resolve the reverse-DNS lookup. Note that this # can happen due to resolver difficulties with the server, delegation # errors at the provider, or any number of other reasons, and should # only be enabled judiciously. Also note that this rule will not fire # if the HELO identifier is an IP address or domain-literal, or if the # 'helo' field is empty. # This stuff seems to have proven pretty stable, so I guess I should find out what's needed to get it formalized -- Eric A. Hall http://www.ehsco.com/ Internet Core Protocols http://www.oreilly.com/catalog/coreprot/
