MX lookup
See which mail servers receive a domain's email, in the order senders will try them, live from a public resolver.
Related tools: SPF checker · DMARC checker · DKIM checker · All free tools
Where a domain's mail is delivered
MX records tell sending mail servers where to deliver email for a domain: each names a mail exchanger and carries a priority, and senders try the lowest number first. An MX lookup returns that list. This tool asks Cloudflare's 1.1.1.1 resolver over DNS-over-HTTPS from outside your network, sorts the answer by priority, and shows the TTL on each record, which is what decides how quickly a mail provider change takes effect.
An MX record that changes without you knowing means mail going somewhere else, and that can go unnoticed for days. Upcheck checks every website's MX records every 6 hours and alerts your team when they change.
Three steps, no signup
- 01
Enter a domain
The part after the @ in an email address, such as example.com.
- 02
We ask a public resolver
The MX query goes over DNS-over-HTTPS to Cloudflare's 1.1.1.1 from Cloudflare's network.
- 03
The mail servers come back in order
Priority first, then hostname, with the TTL alongside each.
Frequently asked questions
What is an MX record?
A mail exchanger record. It names a server that accepts email for a domain and gives it a priority. A sending server looks up the MX records for the recipient's domain, sorts them by priority, and connects to the first one that answers. Most domains publish two or more so that mail is still accepted when one server is down.
What do the MX priority numbers mean?
Preference, with lower numbers preferred. A domain with 10 mail1.example.com and 20 mail2.example.com wants mail delivered to mail1, with mail2 as the fallback. Two records with the same number are equal, and senders spread mail across them. The numbers themselves are arbitrary; only their order matters.
The lookup shows no MX records. Can the domain still receive mail?
Sometimes. If a domain has no MX records, senders fall back to its A record and try to deliver to that address on port 25. Almost nobody runs a mail server that way any more, so in practice no MX records means the domain doesn't receive mail. A domain that is only used for sending should publish a null MX (0 .) to say so explicitly.
I moved to a new email provider. Why is mail still going to the old one?
Because of the TTL on the old MX records: every sending server that looked up your domain recently keeps the old answer until it expires. Mail delivered to the old servers during that window is usually fine if they still forward or accept it, which is why providers advise keeping the old service running for a day. If the lookup here still shows the old records long after the change, check the zone you edited is the one your nameservers serve.
Does an MX record need SPF and DMARC too?
MX handles incoming mail; SPF, DKIM, and DMARC are about the mail you send. They are separate records with separate jobs, and a domain that receives mail correctly can still have its outgoing mail spoofed or junked. Check them with the SPF checker and the DMARC checker.
Is this MX lookup free?
Yes. No account, no limit on lookups by hand; scripted use is rate limited. Upcheck's paid monitoring re-checks every website's MX records every 6 hours as part of its DNS check and alerts your team when they change.
One lookup shows where mail goes. Monitoring shows when that changes.
Add your domains to Upcheck and get alerted by email, Slack, Discord, Teams, or webhook the moment an MX record moves.