How-To

How to do an MX lookup and understand what it tells you

Inboxlogy5 min readUpdated 2026-10-26

In short: To run an MX lookup, open a free MX Lookup tool, enter the domain, and read the mail servers it returns in priority order. The tool also detects the email provider automatically, so you instantly know whether a domain runs on Google Workspace, Microsoft 365, Zoho or something else.

On this page

  1. When should you run an MX lookup?
  2. How to run an MX lookup step by step
  3. How to interpret the results
  4. What to check next

When should you run an MX lookup?

Run an MX lookup when you need to: confirm a domain can receive email, find out which provider hosts a domain's mailboxes, debug bounced mail, verify a migration (for example, after switching to Google Workspace or Microsoft 365), or research a prospect's tech stack before an outreach campaign.

How to run an MX lookup step by step

  1. Open the MX Lookup tool. Go to the free Inboxlogy MX Lookup.
  2. Enter the domain. Type the bare domain, e.g. company.com. No www or https:// needed.
  3. Click Look up MX. The tool queries live DNS and lists every mail server with its priority.
  4. Read the priority order. The lowest number is the primary server. Lower = tried first.
  5. Note the detected provider. The tool labels the provider (Google Workspace, Microsoft 365, Zoho, Proofpoint, etc.) so you don't have to recognise hostnames yourself.

How to interpret the results

A healthy result shows one or more MX hostnames ending in a real mail provider's domain, each with a sensible priority. If you see “No MX records found”, the domain can't receive email. Either it is not configured for mail, or something is broken. If the detected provider isn't what you expected (say, you migrated to Microsoft 365 but still see old MX records), the change either hasn't propagated or wasn't saved correctly.

What to check next

MX records only cover receiving mail. If you're setting up or auditing a domain for sending, especially cold email, the records that decide inbox placement are SPF, DKIM and DMARC. Run the SPF Checker, DKIM Checker and DMARC Checker next to make sure your outbound mail is authenticated.

Run a free MX lookup now

Enter any domain and see its mail servers in priority order, with the provider auto-detected.

Open the MX Lookup tool →All free tools

Frequently asked questions

How do I find a domain's mail server?
Run an MX lookup. Enter the domain into an MX Lookup tool and it returns the mail servers (MX records) that receive email for that domain, listed in priority order.
Is an MX lookup the same as a DNS lookup?
An MX lookup is a specific type of DNS lookup that queries only the MX (mail exchange) records. A general DNS Record Checker returns MX plus A, AAAA, TXT, NS and CNAME records together.
Why does the MX lookup show a provider name?
Good MX tools recognise common mail-server hostnames and map them to the provider. For example, hosts ending in google.com mean Google Workspace. This saves you from memorising which hostname belongs to which service.
Can an MX lookup be wrong?
The lookup reflects live DNS, so it's accurate as of that moment. But if you recently changed your MX records, propagation delays (up to 48 hours) may mean you still see the old servers. Re-check after propagation.

Keep reading

DNS Record CheckerLook up A, MX, TXT, NS in one clickSPF CheckerValidate SPF + the 10-lookup limitDKIM CheckerValidate your DKIM public keyDMARC CheckerRead your DMARC policy in plain English