on Tue, Jan 12, 2010 at 02:59:55PM -0500, Jed Smith wrote: > 4. For other reasons laid out in this thread, PTR is not the best choice. > Additionally, administrators of mailservers who have no idea what a PTR > is -- although their entry fee to the Internet mail system is debatable > it will not be discussed here -- are now punished by blocklists like > SORBS and Trend Micro with the simple crime of not knowing to PTR their > mail server with something that screams "static allocation, not CPE".
Mild correction: it's FAR BETTER to use something that screams I AM A MAIL SERVER WITH A LEGITIMATE PURPOSE AND A COMPETENT ADMIN rather than just using yet another generic static naming convention. :-) Because using generic static naming is falling victim to the rather baseless assumption that all statics should be allowed to send mail, which is just ridiculous. We've got a /27 (we're a web app dev shop) and only one of those IPs is a mail source, one is a NAT, one is a VPN box, several others run Web servers and other services, and so could possibly emit mail but likely only to us, and we can always whitelist if need be. I assume that the case is similar in other organizations; their static IPs far outnumber their canonical mail servers. Of course, I asked for appropriate custom PTRs for all of them, but still - the point stands, especially for those who think that generic static PTRs are sufficient for a modern mail infrastructure. I don't care who your ISP is, I care who you supposedly are, because if I see that your mail server (or other hosts on your network) are infected, compromised, or otherwise sources of abuse directed at my network, I want to deal with /you/, not with your upstream's abuse desk triage. > I note, with a heavy hand, that there are no widely-disseminated > standards governing the reverse DNS of an Internet host other than this > draft, but administrators make decisions on it anyway. On that and on a wide variety of other criteria, yes. -- hesketh.com/inc. v: +1(919)834-2552 f: +1(919)834-2553 w: http://hesketh.com/ antispam news and intelligence to help you stop spam: http://enemieslist.com/