>> IMHO it is not true. Novadays, it is required for a mail server to have a valid >> reverse dns record. But it doesn't have to point back to the same name. It would >> lead to very very poor IP space usage - eg. virtual hosting provider, which has >> 300 domains would need 300 IP's even if all of them are hosted on 1 machine, >> and number of domains can MUCH higher than all of the IPs. I wish! I've run across places that seem to check that the reverse DNS matches the forward DNS name. I've seen it with Comcast and I gotta believe there are others doing it. It is a pain for me because I have to consume a precious IP Address for each email domain I host here. It may be possible that the big hosters know about each other and make special arrangements with each other to which little ol' me is not privvy. If anyone out there has any connections with the Comcast DNS people, I'd love to talk to you about this and other issues - but we're straying off the original topic. - Greg -----Original Message----- From: lartc-bounces@xxxxxxxxxxxxxxx [mailto:lartc-bounces@xxxxxxxxxxxxxxx] On Behalf Of Robert Kurjata Sent: Monday, January 02, 2006 4:02 PM To: lartc@xxxxxxxxxxxxxxx Subject: Re[2]: Fwd: Several IP's, one mail and http server W Twoim liście datowanym 2 stycznia 2006 (18:51:25) można przeczytać: GS> You want multiple IP Addresses for email if you are hosting more GS> than one domain. The reason is, everyone now checks for reverse DNS GS> with email so you need a different public IP Address for each email GS> domain. This way, all the reverse DNS translations will be unique. IMHO it is not true. Novadays, it is required for a mail server to have a valid reverse dns record. But it doesn't have to point back to the same name. It would lead to very very poor IP space usage - eg. virtual hosting provider, which has 300 domains would need 300 IP's even if all of them are hosted on 1 machine, and number of domains can MUCH higher than all of the IPs. mail.domainA.com - WW.XX.YY.ZZ ZZ.YY.XX.WW.in-addr.arpa PTR - host.domainB.com host.domainB.com - WW.XX.YY.ZZ for an egzample one of the bigest portals - yahoo: dig yahoo.com MX - mx1.mail.yahoo.com - 67.28.113.10, 67.28.113.11 dig 10.113.28.67.in-addr.arpa PTR - mta-v4.level3.mail.yahoo.com. dig mta-v4.level3.mail.yahoo.com. - 67.28.113.10 Citation from one of the mail server manuals: If you have a PTR record for your IP address, and the target of the PTR record has an A record pointing back to that same IP address, mail will not be rejected from your server due to an invalid PTR. -- Pozdrowienia, Robert Kurjata _______________________________________________ LARTC mailing list LARTC@xxxxxxxxxxxxxxx http://mailman.ds9a.nl/cgi-bin/mailman/listinfo/lartc _______________________________________________ LARTC mailing list LARTC@xxxxxxxxxxxxxxx http://mailman.ds9a.nl/cgi-bin/mailman/listinfo/lartc
