Take the 2-minute tour ×
Server Fault is a question and answer site for professional system and network administrators. It's 100% free, no registration required.

I'm somewhat green when it comes to network administration, and I'm having some trouble configuring my DNS records so that I can receive e-mail to an e-mail server that I've recently set up. I'm able to send e-mail from the server, I'm just not able to receive mail. The e-mail server is an instance of the Standard Edition of MailEnable. The domain name for the server is of the form mydomain.com. I'm trying to set up the e-mail server to use the sub-domain mail.mydomain.com. Both of these domains point to the same IP address, and everything is running on the same server. When I type in the domain mail.mydomain.com, one of MailEnable's online tools produces an error message which reads:

FAIL, Unable to determine name servers for this domain. This may be because the domain is not registered. Please see www.dnsreport.com for more information on this domain.

This leads me to believe that this is a DNS issue. Could anybody point in the right direction as to how to troubleshoot this? I'm able to successfully ping mail.mydomain.com. Also, when I type nslookup mail.mydomain.com, I'm able to retrieve the mx record

mail.mydomain.com MX preference = 5, mail exchanger = mail.mydomain.com

I'm not really sure what to do, or how to proceed in troubleshooting the issue...

Any help will be much appreciated!

Andrew

share|improve this question
add comment

2 Answers

up vote 2 down vote accepted

The domain name for the server is of the form mydomain.com. I'm trying to set up the e-mail server to use the sub-domain mail.mydomain.com.

I'm assuming that the mail in mail.mydomain.com is really a host, and not a domain. If it is a real sub-domain, you're going to have issues with your setup.

Both of these domains point to the same IP address, and everything is running on the same server.

If you want smooth-running email, you're going to need (at a minimum) in your DNS entries:

  • A valid DNS A record to map the host to the address
  • A valid DNS PTR record to map the address to the host; while not technically necessary, many mail systems enforce the concept of reverse-lookup to determine if the connection received is valid or not. This record will be in your reverse-lookup zone, not your forward-lookup zone.
  • A valid MX record, which should point to mail.mydomain.com in your example

However, you go on to show this:

FAIL, Unable to determine name servers for this domain. This may be because the domain is not registered. Please see www.dnsreport.com for more information on this domain.

This is a problem with your DNS setup in general. You haven't specified a name server for the domain...when a client (or mail server) attempts DNS queries, the net result is "there isn't anyone to talk to". The name server for the domain is a "hint" to others that, when asking about a host in the domain, they should go there.

share|improve this answer
    
Thanks Avery, I appreciate your detailed response. Mind if I ask what you mean when you write "If it is a real sub-domain, you're going to have issues with your setup."? I've configured an A record for mail.mydomain.com, which points to the same server as mydomain.com. Is this a bad idea? Also, I'm going to look into the issue with not specifying a name server, and also creating a PTR record. That's a great idea, and I'm sure I haven't done it... –  Andrew Dec 2 '11 at 20:47
    
I known it's a popular thing to assign the domain to an actual host, and technically you can do it and it'll work, but generally, I'm a bit old-fashioned - I don't assign the domain any address, because it really doesn't need it. If the domain and the mail host will always have the same final address, then you'll be ok. Otherwise, I wouldn't bother. –  Avery Payne Dec 2 '11 at 20:57
    
I'm sorry, I just noticed that I didn't respond to the "subdomain" question. What I meant was, a subdomain may or may not have a different zone file than the parent domain, may have its own independent mail exchanger (MX record), etc. etc. Frankly, unless you have some specific things you need to do with subdomains, I wouldn't bother. –  Avery Payne Dec 3 '11 at 2:20
add comment

So you didn't follow the advice to look at http://www.dnsstuff.com/products/mstc ??

And you didn't try mxtoolbox.com?

If you don't do it, then we need the domain name. Otherwise I say: Yes it is a DNS issue!

share|improve this answer
    
When I tried going to www.dnsreport.com and entering mail.mydomain.com, I just got a page stating "No match for domain mail.mydomain.com". I'm not really sure why this is. mydomain.com is registered via GoDaddy. I tried to configure an mx record for mail.mydomain.com, and A records for mydomain.com and mail.mydomain.com which both point to the same IP address. As for mxtoolbox.com, are those tools for free? I hoping for a simple solution using built-in Windows commands or something else. I'm not sure why 3rd party software should be required... –  Andrew Dec 2 '11 at 20:36
    
Because I assume that your DNS works locally but not from remote. Otherwise use nslookup; that's built-in. –  mailq Dec 2 '11 at 20:37
add comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.