What is an MX record?

An MX (Mail Exchanger) record in DNS says which server should receive mail sent to addresses like info@example.com. Each MX record has two parts: a priority number and the name of a mail server. The lower number wins; if that server is unreachable, the sender tries the next one.

Why it matters

If your domain uses email but has no MX record, or the record points to the wrong server, mail from customers and colleagues does not reach you; it usually bounces back to the sender after a few days of retrying, and you never hear about it. If the domain receives no mail at all, having no MX is fine, which is why CheckNet shows it only as information, not as an error.

Set up your MX records

1. In your email service’s panel (Google Workspace, Microsoft 365 or your web host’s mail, for example), open its domain setup page and copy the MX values exactly from there.
2. In your domain’s DNS panel, find any old MX records that point to a previous service; delete them once the new ones are in place, so mail is not split between two services.
3. For each server, create a record of type MX, name @, with the server name as the value and the priority number the service gave you.
4. If the email service also asks for SPF or DKIM records, add them at the same time.
5. Send a test message from an outside account to your domain and check that it arrives.

example.com.  MX  10 mx1.example-mail.com.
example.com.  MX  20 mx2.example-mail.com.

Common problems

• An IP address instead of a name: an MX value must be a server name, not an IP. Give the server a name with an A record and put that name in the MX.
• Pointing at a CNAME: the standard does not allow an MX value to be an alias (CNAME), and some servers reject it. Use the server’s real name.
• The domain added twice: some panels append your domain to the value, giving something like mx1.example-mail.com.example.com. Check the final value in CheckNet’s records table.
• Two services’ records at once: if the old and new service’s MX records are both still there, part of your mail goes to the old mailbox. Keep only the current service’s records.

When there is no MX record, senders fall back by the standard to delivering to the domain’s own address (its A or AAAA record). If the domain should never receive mail, publish a “null MX” instead of leaving it empty: an MX record with priority 0 and a single dot as the value, 0 ., so senders know at once and do not keep retrying.

Check it with CheckNet

On CheckNet’s DNS page, look at the “has a mail server (MX)” row. The records, with their priority numbers, are in the records table. If you still see the old value, wait a little: DNS changes take minutes to hours, depending on the TTL.