What this tool does
MX (mail exchange) records tell the world which servers accept email for a domain, and in what order to try them. This lookup returns every MX record with its priority (lower is tried first) and TTL, so you can confirm your mail is routed where you expect, or see who handles a domain's email.
Diagnosing where your mail actually goes
Reading MX records is how you confirm mail flows to the right provider. Most managed email uses a recognizable pattern: Google Workspace points at smtp.google.com, and Microsoft 365 uses <tenant>.mail.protection.outlook.com. A common failure is a leftover MX from an old provider sitting alongside the new one, which silently splits inbound mail between two systems. Check the priorities to see which server is primary, and confirm the TTL before a cutover so you know how long stragglers will keep hitting the old host.
Frequently asked questions
What does the MX priority mean?
When a domain has multiple mail servers, the priority number sets the order senders try them. The lowest number is the primary; higher numbers are backups used if the primary is unreachable.
No MX records were found, what does that mean?
A domain with no MX records doesn't receive email at that name. Some setups deliberately have none, or use the A record as a fallback. If you expect mail there, this usually signals a misconfiguration.
How do MX records relate to spam protection?
MX shows where mail is delivered, but SPF, DKIM, and DMARC control who's allowed to send. Use the DNS Reconnaissance or email tools to check those too.
What MX records should Google Workspace or Microsoft 365 use?
Modern Google Workspace uses a single record, smtp.google.com at priority 1 (older setups list five aspmx hosts). Microsoft 365 uses one record shaped like yourdomain-com.mail.protection.outlook.com. If you see MX entries that match neither and you're not running your own mail server, they're likely stale and worth removing.