1. Go to your domain registrar's web site and verify that your domain registration is current, i.e., not expired. If your domain registration is expired, your domain will not function until its registration is renewed. If an expired domain is not promptly renewed, you may permanently lose it to somebody else.

2. If you have a newly-registered domain or a new web-hosting account, also verify at your domain registrar's web site that the nameservers for the domain are configured correctly. For a Directadmin account, the nameserver records must point to the host names you were sent in your welcome email. “Nameserver records” are also sometimes referred to as “NS records” or sometimes as just “nameservers”.

3. Check the validity of your domain at one or more of the free domain-testing web sites below.

• http://www.dnscolos.com/free-dns-report.html
• http://www.intodns.com/
• http://www.centralnic.com/support/doctor
• http://www.checkdns.net/quickcheckdomainf.aspx

Not all of these do exactly the same tests, so we suggest trying more than one of them.

The following warnings are usually harmless:

• Home page or main page redirects somewhere else.
• Your domain has only one one MX record or only one mail server.
• Recursive queries are enabled.
• SOA expire number is not OK.
• Not all of your nameservers are in different subnets or single point of failure.
• Anything related to the mail server greeting.

The following warning might or might not be harmless:

• Connect to mail server failed or attempt to send mail failed.

If greylisting for spam control is enabled on your domain, then an initial attempt to send mail to an address in your domain may fail with a temporary error. This may look like a mail server problem, but isn't really. Consider this type of diagnostic message to reveal a real problem only if you know that your incoming mail is not only failing to arrive, but also actually bouncing back to senders.

Also see: Domain problem.