MX lookup
Enter a domain to see which servers receive its mail, in the order senders try them, with their addresses and the mailbox provider behind them.
How to read the result
Priority: lower is tried first; servers with the same number share the load. Host is the mail server's name, Addresses what it resolves to. A host with no address cannot receive anything, and is marked.
A null MX (0 .) means the domain declares it takes no mail, which is right for a domain that only sends. No MX at all is different: senders then try the web server, and mail usually bounces.
MX records decide who receives mail, not who may send it. For that, see the SPF checker, or run the domain health check.
Questions
- What is an MX record?
- A DNS record that says which servers receive mail for a domain. Each has a priority: senders try the lowest number first and fall back to the next. A domain that receives mail needs at least one.
- What happens if a domain has no MX record?
- Senders fall back to the domain's A record (the implicit MX), which usually points at a web server that does not accept mail, so messages bounce. A domain that should take no mail at all can say so with a null MX: priority 0 and a single dot.
- Does a send-only domain need MX records?
- Not for sending: SPF, DKIM and DMARC are what receivers check. But replies and bounces go to the From or Return-Path domain, so give it MX records if anyone should be able to answer, or a null MX if not.
- Can an MX record point to an IP address?
- No. An MX record must name a host, and that host needs its own A or AAAA record. Many senders skip an MX that is an IP address.
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