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MX Lookup
MX Lookup checks a domain’s mail exchanger records, priorities, TTL values, and receiving mail servers so you can verify email DNS routing.
What MX Lookup does
MX Lookup gives you a fast, focused view of the Mail Exchanger records that control inbound email delivery for a domain. Use the result to identify receiving mail servers, compare MX priorities, review TTL values, and confirm that live DNS matches the configuration expected by your email provider. This is especially useful after a mail migration, DNS update, provider change, or delivery incident.
An MX record does not contain an IP address directly. Instead, it points to a hostname for a receiving mail server. Sending systems query these records before attempting delivery, which makes an accurate MX configuration an important part of reliable email infrastructure.
How to use
Enter a domain name such as gmail.com without a protocol, path, or email address. Select Look Up MX Records, then review every returned mail exchanger, its numeric priority, and its TTL. Lower priority numbers are normally preferred first. If several records have the same priority, they may act as equivalent delivery targets.
Compare the live result with the MX values documented by your mail provider. Check for obsolete hosts, typing errors, unexpected providers, and records left behind after a migration. If an MX hostname looks suspicious, use the related DNS and network tools on Trexmi to investigate it further.
Why use MX Lookup?
Focused controls, predictable output, and a workflow designed around this exact transformation.
MX Lookup reveals the active mail route
See the mail exchanger hostnames currently returned by DNS instead of relying only on settings shown in a provider dashboard.
Compare MX priorities quickly
Review preference values in one result so you can understand which receiving servers should be attempted first.
Review DNS TTL values
TTL information helps explain why old MX answers may remain visible in recursive resolver caches after a change.
Questions about MX Lookup
Practical details about input, output, privacy, limits, and the best way to use this tool.
01 What does MX Lookup show?
MX Lookup shows the mail exchanger records returned for a domain, including receiving hostnames, priority values, and available TTL information.
02 Does a lower MX number have higher priority?
Yes. In normal MX routing, a lower preference number is tried before a higher number.
03 Why can an old MX record still appear?
DNS resolvers can cache earlier answers until their TTL expires, so recent changes may take time to appear consistently.
Read the HTTP Headers Guide
Connect DNS, redirects, HTTP headers, requests, responses, caching, security, and practical web diagnostics.
- Requests and response headers
- Redirect and cache diagnostics
- Security and API debugging
MX Lookup checks that help diagnose email delivery
When mail stops arriving, start by confirming that the domain actually publishes the expected MX records. A missing record, an old provider hostname, or an incorrect priority can send delivery attempts in the wrong direction. The live DNS answer is therefore a useful first comparison point when troubleshooting.
What MX priority means
Each MX record includes a preference number. In normal SMTP routing, lower numbers have higher preference, so priority 10 is generally attempted before priority 20. Multiple records can provide redundancy, while equal priorities can allow delivery systems to choose between equivalent targets. Priority alone does not prove that a mail server is healthy; it only describes the order published in DNS.
MX Lookup and DNS propagation
DNS changes are not always visible everywhere at the same moment. Recursive resolvers can retain a previous answer until its TTL expires. If you recently changed mail providers, compare the current MX Lookup result with the new provider configuration and allow for caching before assuming the update failed.
7 powerful MX checks before you finish
Verify the domain name, confirm every expected exchanger is present, compare priorities, inspect TTL values, remove obsolete provider records, confirm each exchanger hostname resolves correctly, and test related public services when necessary. These checks catch many common configuration mistakes without requiring access to the destination mail server.
Related DNS and network tools
Use DNS Lookup to inspect A, AAAA, TXT, NS, SOA and other DNS data. Use NS Lookup to verify authoritative nameservers, and Port Checker when you need to test whether a public service port can be reached. For the protocol background behind SMTP routing, consult RFC 5321. General DNS root and delegation information is also available from IANA.
Why use MX Lookup on Trexmi
The tool keeps the task narrow: enter a domain, retrieve its MX answer, and review the fields that matter for mail routing. It is useful for administrators, developers, support teams, and domain owners who need a readable confirmation of the DNS configuration currently visible from the Trexmi server environment.