nanog mailing list archives
Re: AOL rejecting mail from IP's w/o reverse DNS ?
From: Suresh Ramasubramanian <suresh () outblaze com>
Date: Wed, 03 Dec 2003 12:08:24 -0500
Jeffrey Paul writes on 12/3/2003 11:39 AM:
Perhaps I'm being naïve, but this seems like a very good way to cause spammers to suddenly start having valid PTR RRs. Thoughts?
A lot of spam these days comes from trojaned windows machines on dialup / broadband IPs.
Most ISPs in the USA and the world over already have generic PTR records (ip-foo-bar.ppp.provider.net and such) on their dhcp pools.
So, yes, the mere presence of rDNS for an IP is not an indicator that the traffic coming at your mailserver from that IP is not spam.
On the other hand, the absence of rDNS on an IP seems to often be accompanied by assorted other brokenness, such as open relays / proxies and compromised hosts.
-- srs (postmaster|suresh)@outblaze.com // gpg : EDEDEFB9 manager, outblaze.com security and antispam operations
Current thread:
- RE: AOL rejecting mail from IP's w/o reverse DNS ?, (continued)
- RE: AOL rejecting mail from IP's w/o reverse DNS ? Tony Hain (Dec 04)
- RE: AOL rejecting mail from IP's w/o reverse DNS ? Sean Donelan (Dec 04)
- Re: AOL rejecting mail from IP's w/o reverse DNS ? Petri Helenius (Dec 07)
- Re: AOL rejecting mail from IP's w/o reverse DNS ? just me (Dec 07)
- Re: AOL rejecting mail from IP's w/o reverse DNS ? Suresh Ramasubramanian (Dec 04)
- Re: AOL rejecting mail from IP's w/o reverse DNS ? Petri Helenius (Dec 03)
- RE: AOL rejecting mail from IP's w/o reverse DNS ? Tony Hain (Dec 04)
- And your solution is? (was RE: AOL rejecting mail from IP's w/o reverse DNS ?) Sean Donelan (Dec 04)
- Re: AOL rejecting mail from IP's w/o reverse DNS ? Suresh Ramasubramanian (Dec 03)
- Re: AOL rejecting mail from IP's w/o reverse DNS ? Dave Howe (Dec 03)
- Re: AOL rejecting mail from IP's w/o reverse DNS ? Suresh Ramasubramanian (Dec 03)