When email delivery fails, the first DNS question is often straightforward: which servers does the domain publish for incoming mail? MX records answer that question. They are routing instructions for mail systems, not a guarantee that a mailbox exists or that a message will be…
When email delivery fails, the first DNS question is often straightforward: which servers does the domain publish for incoming mail? MX records answer that question. They are routing instructions for mail systems, not a guarantee that a mailbox exists or that a message will be accepted.
What WebLens returns
The WebLens MX Lookup queries the domain’s public MX records and displays each mail host with its priority. Records are sorted by priority so you can see preferred destinations first.
How MX priority works
MX records contain a numeric preference value. Lower values have higher preference, so a sender generally tries the lowest number first and can use higher numbers as alternatives. A domain may publish one server or several for redundancy.
The hostname matters too: the MX record points to a mail server name, which then needs to resolve to reachable addresses.
How to troubleshoot
- Enter the domain whose incoming mail you are investigating.
- Run the WebLens MX Lookup.
- Confirm that the returned hosts match the mail provider you expect.
- Check priorities if multiple servers are published.
- Use the DNS Lookup to inspect related A or AAAA records.
Example: a domain still points to the old provider
Imagine a company moved email providers but its MX records still point to the old service. New senders can continue delivering mail according to those public records until DNS changes propagate. An MX lookup makes the routing mismatch visible quickly.
Example: one mail server is unavailable
A domain with several MX records may be designed for redundancy. If the preferred server is unavailable, sending systems can attempt another eligible server according to SMTP and DNS behavior. Multiple records do not automatically guarantee resilience; the mail servers must also be configured correctly.
What an MX record does not tell you
An MX lookup does not verify a mailbox, authenticate a sender, or prove that a receiving server will accept a particular message. Delivery also depends on SMTP responses, SPF, DKIM, DMARC, reputation, rate limits, filtering, mailbox state, and provider policies.
Why an empty result needs context
A domain without MX records does not necessarily mean its website is broken. Web hosting and email hosting are separate services. A domain can serve a healthy website while intentionally having no mail service.
Propagation and caching
After changing MX records, different resolvers may hold older answers until cached TTLs expire. WebLens reports the records available to its resolver at check time. During a migration, repeat the check and compare it with the authoritative DNS configuration.
Check the routing record directly: open the WebLens MX Lookup and see which mail servers the domain currently publishes.
MX records are only the start of mail troubleshooting
Once you confirm the intended MX hosts, the next question is whether those hosts resolve and respond as expected. An MX record can point to a hostname that has a DNS problem, a service that is unavailable, or a provider that is rejecting mail for policy reasons. Use DNS and SMTP evidence together.
For authentication problems, inspect SPF, DKIM, and DMARC configuration separately. These controls influence whether receiving systems trust a message, while MX records describe where inbound mail should be delivered. Keeping those roles separate makes email troubleshooting much clearer.
Priority does not mean load balancing
MX preference values primarily express delivery preference. They should not be interpreted as a simple percentage split of traffic. If several servers have the same preference, sender behavior can vary, while higher numeric values are generally fallback choices. The receiving infrastructure must still be designed to handle the traffic it may receive.