Priority decides the order
Each MX record has a priority number. Sending servers try the lowest number first and fall back to higher ones if it does not answer.
Two records with the same priority share the load.
MX record lookup
Enter a domain to list its mail servers, their priority and the email provider behind them.
Free, no signup. Up to 10 checks per hour.
What MX records tell you
MX (mail exchange) records list the servers that receive email for a domain, and in what order.
The host shows the provider
Hosts ending in google.com point to Google Workspace, and hosts ending in outlook.com point to Microsoft 365.
Knowing the provider helps when you guess an email format or plan a cold email campaign.
No MX means no mail
A domain without MX records cannot receive email, so any address on it will bounce.
Check MX before you verify a list. It is the fastest way to spot dead domains.
Need more than one check?
Warm up new mailboxes and watch SPF, DKIM, DMARC and blacklists for every inbox you connect. See Email Warmup
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MX Lookup FAQ
Related free tools
What is an MX lookup?
An MX lookup reads the DNS records that name the mail servers for a domain. It shows where email for that domain is delivered and in what order the servers are tried.
Why does a domain have several MX records?
Backup and load sharing. If the server with the lowest priority number is down, senders try the next one. Records with equal priority split the traffic.
What does it mean if a domain has no MX records?
The domain is not set up to receive email. Messages sent to any address on it will bounce, unless the domain has an A record that a few older servers still try as a fallback.
Can MX records show which email provider a company uses?
Usually, yes. Most providers use recognizable hostnames, for example google.com for Google Workspace and protection.outlook.com for Microsoft 365. Security gateways like Proofpoint or Mimecast can hide the provider behind them.
How long do MX changes take to show up?
It depends on the TTL set on the record, often between a few minutes and a few hours. This tool asks public DNS resolvers, so it sees what the rest of the internet sees.
