MX Record Checker
Look up the mail servers for a domain.
Enter a domain to look up its MX records, see which mail servers accept its email and in what order they are tried. We read the live records straight from DNS over an encrypted connection. Nothing is stored.
This tool looks up the MX (Mail Exchanger) records for a domain: the DNS entries that tell sending servers which hosts accept inbound email and in what order. Each MX record pairs a preference number with a hostname; a lower preference value is tried first, and equal values share load. Getting MX right is the foundation of email delivery: if these records are wrong or missing, mail to your domain bounces or is lost.
How to read the result
The tool resolves each MX hostname to its IP addresses so you can confirm the targets exist. A correct setup points MX records at your mail provider's hostnames (for example a Google Workspace or Microsoft 365 host), not at IP literals. MX values must be hostnames, never bare IP addresses or aliases. Watch for a few classic faults: an MX that resolves to a CNAME (which violates the spec and breaks some senders), a trailing dot or typo in the hostname, or a stale record left over from a previous provider. If no MX exists, senders may fall back to the domain's A/AAAA record, which is rarely what you want.
Why MX matters for authentication
MX records identify your inbound servers, but they also anchor several outbound-security checks. DANE/TLSA records are published per MX host, and MTA-STS policies list the permitted MX hostnames, so an inconsistency between your real MX set and these policies will block delivery. Verifying MX is therefore the first step in an email audit. Once inbound is sound, lock down outbound spoofing with DMARC; our done-for-you service handles the enforcement journey for you.
Frequently asked questions
What does the preference number in an MX record mean?
It sets the order in which senders try your mail hosts: the lowest preference value is attempted first, and higher values act as backups. Records that share the same preference are used roughly evenly, which is how administrators balance load across multiple servers.
Can an MX record point to an IP address?
No. An MX value must be a hostname that resolves to an A or AAAA record. Pointing it at a bare IP, or at a CNAME alias, is invalid and will cause delivery failures with strict senders.
What happens if a domain has no MX records at all?
Sending servers fall back to the domain's A/AAAA address and attempt delivery there, which usually fails or routes mail to the wrong host. Any domain that receives email should publish explicit MX records rather than rely on this fallback.
Do MX records affect whether my outgoing email is trusted?
Not directly. Outbound trust comes from SPF, DKIM and DMARC. But MX records anchor inbound-security policies: MTA-STS lists your permitted MX hostnames and DANE publishes TLSA records per MX host, so a mismatch between your real MX set and those policies can block mail.
Why does my MX hostname resolving to a CNAME cause problems?
The mail specification requires an MX target to point to an address record, not to another alias. Some sending servers refuse to follow a CNAME at an MX target, so delivery becomes unreliable even though the name appears to resolve.
I switched email providers, so why is old mail still going to the wrong place?
You almost certainly left a stale MX record from the previous provider, or it is still cached for the duration of its TTL. Remove the obsolete records, confirm only your current provider's hosts are listed, and wait for the old TTL to expire before testing again.