>... >On 10/23/2006 7:01 PM, John Rudd wrote: >> Eric A. Hall wrote: >>> http://www.ehsco.com/misc/spamassassin/std_compliance.cf might help or >>> work for what you're doing. >>> >>> Make sure to read the disclaimers and warnings >> >> Those helped a lot. There's only three checks I can't do with them >> (probably need to use a plugin for it): >> >> a) does the hostname in the PTR record point to a CNAME instead of an A >> record > >That's not illegal. It's pretty common too, since subnet delegation of >in-addr space only works on /8, /16 and /24 subnets due to the way that >octets are mapped to domain name labels in that hierarchy. >
Eric, I think you either misread, or have it backwards; Indeed a PTR to a CNAME is illegal (RFC not on the fingertips at the moment). What is *very* common is a CNAME to a PTR (which *is* legal). Example: % host 64.32.188.109 109.188.32.64.in-addr.arpa is an alias for 109.104/29.188.32.64.in-addr.arpa. 109.104/29.188.32.64.in-addr.arpa domain name pointer smtp.mpa0.Plectere.COM. >> b) does the hostname contain it's IP address in _hex_ form (instead of >> in decimal form, which I've already got working) > >I don't recall ever seeing that. If you create a rule for that you might >also want to do octal notations too, which is another valid address >encoding syntax that should never appear naturally. > >> c) does the hostname in the PTR record actually going to an A record >> which includes the relay's IP addr > >that's a reasonable test Also called FCrDNS (i.e. "Full Circle reverse DNS"). > >-- >Eric A. Hall http://www.ehsco.com/ >Internet Core Protocols http://www.oreilly.com/catalog/coreprot/ > Paul Shupak [EMAIL PROTECTED]