MX Lookup - View a domain’s mail exchange (MX) records (Updated Jul 2026)


Description:
MX Lookup queries the Mail Exchange (MX) records for a domain and lays out exactly how its email is routed. For each mail server it shows the preference (priority) value, the exchange host name, the record’s TTL in seconds, and the A/AAAA host addresses that the server resolves to. Alongside each record it adds a plain-language note explaining whether it is a higher- or lower-priority target and, where the host name gives it away, hints at the mail provider — for example Microsoft 365 / Exchange Online Protection or Google Workspace. Records are sorted with the most preferred first, a status line summarises the results, and the whole set can be exported to a text file or CSV.


How to use:


1. Enter the domain. Type the domain you want to check into the Domain box (for example example.com).

2. Run the lookup. Click MX Lookup. The query runs in the background, so you can click Cancel at any time to stop it.

3. Read the results. The MX Results list shows each mail server in priority order, with its Preference, Exchange host, TTL in seconds, resolved Host Addresses (IPv4 A and IPv6 AAAA records), and a Notes line. Remember that lower preference numbers are higher priority — mail is delivered to the most preferred server first, and falls back to the others if it is unavailable.

4. Check the summary. The status line at the bottom reports how many MX records were found, the best (lowest) preference value, and how many of the mail hosts resolved to A/AAAA addresses.

5. Export if needed. Once results are shown, click Export to Text File or Export to CSV to save them for a report, an audit trail, or your own records.

What You Can Do With This Program

Potential Uses for MX Lookup Tool:

• Email Delivery Verification: Confirm that a domain’s MX records are configured correctly, so mail can be sent and received reliably.


• Troubleshooting Email Issues: Track down delivery problems by examining the MX records, their preference order and whether each mail host resolves to a valid A/AAAA address.


• Identifying the Mail Provider: Use the exchange host names and the built-in notes to see at a glance whether a domain routes mail through Microsoft 365 / Exchange Online Protection, Google Workspace, or another service.


• Migration and Cut-over Checks: Validate that mail routing has fully transitioned after moving a domain to a new email host, and that the expected servers are now the preferred targets.


• Change and Configuration Review: Check for unexpected changes to MX records and confirm the current setup matches what you expect during routine reviews.


• Learning and Teaching: Demonstrate how email routing and DNS work, using real-time lookups to show preference values, TTLs and host resolution.


• Reporting and Documentation: Export the current MX records to text or CSV for audits, records or hand-over documentation.


• Working Across Several Domains: Look up domains one after another and export each result, keeping a consistent record of mail routing across a portfolio of domains.