How MX records work
When someone sends you an email, their server looks up the MX records for the part after the @. It connects to the server with the lowest priority number and only tries the next one if that fails.
yourdomain.com. MX 10 mx1.mailprovider.com.
yourdomain.com. MX 20 mx2.mailprovider.com.Here mx1 receives everything, and mx2 takes over when mx1 is unreachable.
What the lookup shows
- Every MX record, in the order senders will try them.
- The mail provider behind them, when we recognise it: Google Workspace, Microsoft 365, Zoho, Proton, Olvane and others.
- Mail servers whose hostname doesn't resolve to an IP address, which means mail sent there is lost.
- A null MX (
0 .), which a domain publishes to say it never accepts mail.
Changing your mail provider
Moving email to a new provider means replacing your MX records. Lower the TTL a day ahead, create the new mailboxes first, switch the MX records, and keep the old mailboxes for a few days. Our guide to getting a professional email address covers the whole process, and the email DNS checker confirms SPF, DKIM and DMARC once you've switched.