Kathy as Travis stated you can find the domain holding the IP address in system settings.
My server is imail.k12.de.us, the FQDN, which has the DNS entry, this is strictly for the host itself. We are different here as we accept mail via Ironport gateways (where we do these same checks that Yahoo is probably doing). Ironports route to exchange and an exchange connector routes to Imail. Outbound it goes Imail to exchange and out the firewall. So the only checks against our Imail would be the envelope verification checks if the receiving mail server performs this check. There are two DNS checks, the host check, where your server connects to Yahoo and the check is made. They are verifying that the sending host is what it says it is. Yahoo will most likely check for an A record and a matching reverse entry. So you need one DNS entry and an associated reverse pointer for the FQDN of the server. The second check, is the envelope check, we do this with our Ironports. The sending address is checked for an A-record and a matching reverse pointer. We check that the domain of the sender is valid. So, mail from yahoo.com is checked to see if yahoo.com has a valid A-Record and the reverse pointer. If not, we bounce it as an invalid sender domain. It used to be bad practice to have A-records assigned to your domain, but most big mail systems do this check and without it mail doesn't always work as you'd think. We use unassigned ip addresses for this. The DNS check will work as it resolves, but there is no host or anything physical associated to it. James W. Herron Department of Technology and Information 801 Silver Lake Blvd. Dover, De 19904 [EMAIL PROTECTED] (P) 302-739-9657 (F) 302-739-7243 From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Kathy Lees Sent: Tuesday, December 18, 2007 1:34 PM To: [email protected] Subject: Re: [IMail Forum] Questions for Mail hosts I'm honestly not sure what you mean by IPd domain. ----- Original Message ----- From: Travis Rabe <mailto:[EMAIL PROTECTED]> To: [email protected] Sent: Tuesday, December 18, 2007 11:31 AM Subject: RE: [IMail Forum] Questions for Mail hosts Which domain is your IPd domain - not virtual? Travis From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Kathy Lees Sent: Tuesday, December 18, 2007 10:21 AM To: [email protected] Subject: Re: [IMail Forum] Questions for Mail hosts So, our server name is OSPWeb02 and it is on 64.7.207.173 I have asked that an "A" record is set up pointing OSPWeb02.ltcconnection.com to 64.7.202.173 so we can have FQDN mail.ltcconnection.com reverses to 64.7.202.212.. is this going to solve the problem? I feel like I am in over my head here and don't know what direction to go in. 90% of our domains have their mail record set up to point to 64.7.202.222 because that is the IP their domain is set to. Should they all point to something different? ----- Original Message ----- From: Travis Rabe <mailto:[EMAIL PROTECTED]> To: [email protected] Sent: Tuesday, December 18, 2007 11:14 AM Subject: RE: [IMail Forum] Questions for Mail hosts Technically they don't all need to match, BUT your IPd OHN does need to have reverse DNS. There is nothing stating that for all forwards, it has to have a matching reverse. HOWEVER, your Main IP'd domain does need to have a reverse that matches the OHN. Travis From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Kathy Lees Sent: Tuesday, December 18, 2007 10:10 AM To: [email protected] Subject: [IMail Forum] Questions for Mail hosts I have been going back and forth on this and can't seem to get the answers my boss wants. So I am hoping you guys can help me. We have a few hundred email accounts using our mail server as virtual mail accounts. Of course, when a reverse dns is done, the lookup does not match the domain name it was sent from and messages are being rejected. We have been told that we would have to get a different IP address for each domain, which isn't feasable. How do other hosting companies handle this issue? I can't imagine we are the only ones. Any help, suggestions would be appreciated. Kathy
