On Dec 27, 2007 8:46 AM, David Brown <[EMAIL PROTECTED]> wrote: > On Thu, Dec 27, 2007 at 04:51:31AM -0800, John H. Robinson, IV wrote: > > >> In fact my own server will not accept mail from "UNKNOWN" hosts ( it > >> resolves the hostname, then resolves the IP PTR, and compares the > >> hostname and the resulting PTR record ) > > > >Please fix your mail host. It is breaking the internet. > > > >> The hostmaster for sparkplug.kernel-panic.org needs to ask the IP > >> address provider to add the PTR record ( it should point back to > >> "sparkplug.kernel-panic.org" ). > > > >I disagree. The RFC disagrees. > > The RFC only says that it cannot reject the message. It can still use this > information to help determine if the message is spam. It is similar to SPF > records. The host cannot reject the message at the SMTP level (and comply > with the RFC) but is certainly free to reject it. > > Spam has caused lots of awful breakage of protocols. It's very annoying. >
So has identity theft. Two of my clients require a reverse DNS lookup that must match the domain name for mission critical servers as part of their identity theft prevention policy. Mail, and anything else that doesn't resolve a PTR, gets rejected. It has caused countless needless sporadic outages and innumerable headaches for me. Robert Donovan -- [email protected] http://www.kernel-panic.org/cgi-bin/mailman/listinfo/kplug-list
