MX Record DNS — What It Is and How to Check [2026]

Enterno.io Editorial Team

MX record: Definition, Syntax, and Examples

By Anatoly Oshmanovsky · Updated Apr 17, 2026

TL;DR:

MX (Mail Exchange) is a DNS record type that specifies mail servers for a domain. It contains a priority (lower number = higher priority) and the hostname of a mail server. Without MX records a domain cannot receive email. Multiple MX records are used for failover.

Try it now — free →

What is a MX record

Check MX record online

Use the Enterno.io tool — enter a domain, get results in 1-2 seconds. Free, no signup.

Check →

Domain MX RecordsAll domain mail servers

MX PriorityMail delivery order

Record TTLMX record caching time

MX Server A RecordsIP addresses of mail servers

Why teams trust us

all servers with priorities

SPF

compatibility check

<1s

DNS query

Free

no limits

How it works

Enter domain

Query MX DNS records

Get servers and IPs

What are MX Records?

MX (Mail Exchanger) records specify which server receives email for a domain. When there are email problems, MX records and their priorities are the first thing to check.

All MX Records

Complete list of MX servers with priorities and TTL.

Server A Records

Resolve MX hostnames to IP addresses for the full picture.

SPF Compatibility

Check if MX servers are included in the domain's SPF record.

Real DNS Query

Direct query to authoritative DNS without caching.

Who uses this

Email marketers

deliverability diagnostics

Sysadmins

mail server setup

Developers

email API integration

DevOps

post-mail migration check

Common Mistakes

❌

Single MX serverIf the only MX fails, email is rejected. Use 2+ MX servers with different priorities.

❌

MX not in SPFMX servers must be allowed by the SPF record to send on behalf of the domain.

❌

Wrong priorityLower number = higher priority. 10 = primary server, 20 = backup.

❌

CNAME as MX hostnameRFC 2181 forbids CNAME as MX value. Use only A/AAAA records.

Best Practices

✓

Use 2+ MX serversPrimary with priority 10, backup with priority 20.

✓

Sync MX and SPFAfter adding a new MX server, update the SPF record.

✓

Monitor MX TTLTTL 3600 is optimal. Lower to 300 before changing mail providers.

✓

Check after mail migrationAfter migrating to a new provider, ensure MX records updated globally.

Monitor MX records automatically

DNS monitor notifies when your domain MX records change.

Learn more

Glossary

MX record: Definition, Syntax, and Examples

Frequently Asked Questions

How does MX record differ from similar concepts?

See the full breakdown in the article above. For a quick check, use our online tool.

Does this need manual updates?

Usually no — most modern services configure it automatically. Manual setup is only needed for migrations or exotic configurations.