About the MX Lookup
When a message is sent to someone@example.com, the sending server asks DNS for the MX records of example.com and delivers to the host with the lowest priority number, falling back to the next one if that host does not answer. This page shows those records exactly as the resolver returns them, sorted by priority, with the TTL of the answer. From the hostnames it also names the provider when the pattern is unmistakable: aspmx.l.google.com is Google Workspace, mail.protection.outlook.com is Microsoft 365, and so on.
It is the first check to run when mail bounces. No MX records at all means the domain does not receive email, or relies on the older behaviour of delivering to the A record. Records pointing at a provider the company no longer uses explain silently lost mail after a migration. Two providers listed at the same priority usually means a half-finished change.
The lookup runs through our edge function against Cloudflare's resolver; only the domain name is sent, and it is not kept. For the SPF and DMARC policies that sit next to MX in a well-run domain, query the TXT records in the DNS lookup.
How to use
- Enter the domain part of the address, such as example.com.
- Press Look up and read the servers from the top; the lowest priority is tried first.
- Check the provider line against what the domain owner expects.
- Copy the list or download it.
Common questions
- What does the priority number mean?
- Lower is preferred. A sending server tries the lowest number first and only moves to higher numbers if delivery fails. Equal numbers are tried in random order for load sharing.
- The domain has no MX records. Can it still receive mail?
- Older mail servers fall back to the domain's A record, but most providers treat a missing MX as undeliverable. A domain that wants email should publish at least one MX record.
- Is the provider guess reliable?
- It is based on well-known hostnames only. A custom hostname that forwards to a provider will show no provider line; the hostname itself is still correct.