I am trying to create a mail server. I bought the domain mastermails.info on godaddy.com. I am struggling with the setup of DNS. Whenever I change something in the MX record to make my server available for receiving emails by SMTP, I break something in the SPF record. Whenever I try to fix the SPF record, I get errors from the Kitterman testing tools, that it's not valid:

The TXT records found for your domain are:
v=spf1 mx ptr ip4: ptr:mastermails.info mx:secureserver.net -all

Checking to see if there is a valid SPF record.

Found v=spf1 record for mastermails.info:
v=spf1 mx ptr ip4: ptr:mastermails.info mx:secureserver.net -all

Results - PermError SPF Permanent Error: CNAME loop

I need help with the setup of DNS. My mail server is hosted on ip with domain: mastermails.info. Here I want to have IMAP server and SMTP server. How to setup MX and PTR records to make it work? The biggest problem I have with reverse DNS not found error that I get whenever I want to send something by SMT using my mail server.


The reverse DNS (PTR) records need to be setup with your ISP - the entity that gave you the static IP address assignment. Also for IMAP mailbox access, MX records don't factor in - only for sending email via SMTP.

Looking at your MX records, they seem completely misconfigured. Typically, the priority is, from highest to lowest starting at 10,20,30,etc...This site should offer some insight: MX Record Explanation

As to the current MX record, smtp.mastermails.info isn't resolving for me and smtp.secureserver.net resolves to a different IP than the one you specified in your post, which means the SPF record won't even validate.

You need to fix the MX record to point to the appropriate SMTP servers, have your ISP configure your reverse DNS appropriately and build a proper SPF record (I've had success with this wizard in the past: SPF Wizard).

  • My host is Azure Platform and as far as I know I have to setup reverse dns in txt -> spf records. GoDaddy offers priority from lowest to highest. smtp.mastermails.info isnt resolivng because my server is down at the moment – user2279379 May 30 '14 at 13:14
  • Your ISP needs to configure the reverse DNS for your IP address. They control the reverse DNS for that zone since they own that netblock. smtp.mastermails.info is the DNS name which GoDaddy's DNS servers is set to resolve (GoDaddy being the SOA of the mastermails.info DNS zone) for clients wanting to reach that server; your server being online or not shouldn't affect a DNS resolver being able to resolve the DNS name of the server to its IP address. – Mark May 30 '14 at 13:23
  • I see thankyout for help. I found that Azure platform doesnt offer reverse dns setup... – user2279379 Jun 2 '14 at 19:03
  • I used your spf wizard to create spf record and I got this: v=spf1 mx a ~all Unfortunately I get "Results - PermError SPF Permanent Error: CNAME loop" when checking if spf is valid. – user2279379 Jun 2 '14 at 19:31

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