> So then it's recommended to white list the Hotmail, Yahoo, AOL, MSN, > Verizon, Mindspring, Netzero, and Juno domains because they have so > many mail servers? If so, which others did I leave out?
It doesn't have to do with how many mail servers there are, but everything with how they send mail out. See <http://www.greylisting.org/articles/whitepaper.shtml> for a detailed description of the hows, whats, and whys or greylisting. Two behaviors in particular from some large providers break greylisting: 1.) The resent mail comes from a different hostname/IP 2.) The resent mail comes with a different envelope From: Note #2 is not even RFC821 compliant. Look here for a list of hosts to whitelist <http://cvs.puremagic.com/viewcvs/greylisting/schema/whitelist_ip.txt?rev= 1.16&view=markup> Some of those I wouldn't even bother (do you really want to be getting mail from joker.com?) Note hotmail/live.com and many other very large providers aren't on the list. One can infer that neither of these types of retry behavior isn't necessary for solving scalability issues. ~JasonG -- ~ Ninja Email Security with Cloudmark Spam Engine Gets Image Spam ~ ~ http://www.sunbeltsoftware.com/Ninja ~
