What does the MX priority number mean?

Senders try the lowest number first and fall back to higher ones. Equal numbers share the load between servers.

Do I need more than one MX record?

It is not required, but a second host means mail queues somewhere instead of bouncing when your primary server is down.

Can an MX record point at an IP address?

No. MX values must be hostnames that resolve to addresses; an IP there breaks delivery for strict senders.

What are MTA-STS and TLS-RPT?

MTA-STS tells sending servers to require encrypted, authenticated connections to your mail hosts, and TLS-RPT gives you reports when that fails.

Why does the provider say self-hosted?

The hostnames do not match any well-known mail platform, so the mail is likely handled by your own or your host's server.

MX & Mail Server Checker

See which servers accept a domain's mail and whether its policies are set.

Support

No Login

No API

Domain

Enter a domain to see which mail servers accept its email and whether the sender policies are in place.

About the MX & Mail Server Checker

Resolve a domain's MX records in priority order, resolve each mail host to its IPv4 and IPv6 addresses, identify the mail provider behind them, and check the supporting records: SPF, DMARC, MTA-STS and TLS reporting. Findings flag missing backups, hosts that do not resolve and policies that are not published.

Examples

Check a domain

example.com

Output

MX hosts with priority, IPs and provider

Keyboard shortcuts

Copy the main outputCtrl / ⌘ + Shift + C
Download the resultCtrl / ⌘ + S
Share this toolCtrl / ⌘ + Shift + S
Reset the inputsAlt + R
Open the tool search paletteCtrl / ⌘ + K

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Frequently asked questions

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Version 1.0.0 · Updated 2026-09-16 · Runs entirely in your browser