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RE: Reverse DNS RFCs and Recommendations
From: "Tony Hain" <alh-ietf () tndh net>
Date: Thu, 31 Oct 2013 15:49:56 -0700
John Levine wrote:
Right. Spam filtering depends on heuristics. Mail from hosts without matching forward/reverse DNS is overwhelmingly bot spam, so checking for it is a very effective heuristic.
Leading digit is clearly in widespread use beyond 3com & 1and1. One of the most effective heuristics in my acl list is: \N^.*@\d{3,}\.(cn|com|net|org|us|asia) In the last few hours it has picked off multiple messages from each of these: Carol28 () 8447 com Jeff17 () 3550 com Ronald79 () 0785 com Kevin57 () 2691 com Deborah76 () 3585 com Kimberly34 () 5864 com Sarah94 () 0858 com zavfdv () 131 com qgmklyysyn () 163 com pjpeng () 163 com fahuyrw () 163 com Daniel57 () 4704 com Helen95 () 2620 com
Current thread:
- Re: Reverse DNS RFCs and Recommendations, (continued)
- Re: Reverse DNS RFCs and Recommendations Joe Abley (Oct 30)
- Re: Reverse DNS RFCs and Recommendations Scott Howard (Oct 30)
- Re: Reverse DNS RFCs and Recommendations Mark Andrews (Oct 30)
- Re: Reverse DNS RFCs and Recommendations William Herrin (Oct 30)
- Re: Reverse DNS RFCs and Recommendations Valdis . Kletnieks (Oct 30)
- Re: Reverse DNS RFCs and Recommendations Barry Shein (Oct 30)
- Re: Reverse DNS RFCs and Recommendations Matthias Leisi (Oct 30)
- Re: Reverse DNS RFCs and Recommendations John Levine (Oct 31)
- RE: Reverse DNS RFCs and Recommendations Tony Hain (Oct 31)
- Re: Reverse DNS RFCs and Recommendations John Levine (Oct 31)
- Re: Reverse DNS RFCs and Recommendations Scott Howard (Oct 31)