Free MX Record Lookup — Find Mail Servers for Any Domain
Email not arriving? MX records are the first thing to check. They tell the internet where to deliver email for your domain — get them wrong and messages vanish silently.
Check MX records now: Our free DNS Lookup Tool shows MX records with priorities, plus SPF and DMARC analysis, for any domain.
What Are MX Records?
MX (Mail Exchange) records are DNS records that specify which servers handle email for a domain. Every MX record has two parts:
- Priority — A number (lower = preferred). Mail servers try the lowest-priority server first.
- Mail server hostname — The server that accepts email for the domain.
Example MX records for a domain using Google Workspace:
example.com. 3600 IN MX 1 aspmx.l.google.com.
example.com. 3600 IN MX 5 alt1.aspmx.l.google.com.
example.com. 3600 IN MX 5 alt2.aspmx.l.google.com.
example.com. 3600 IN MX 10 alt3.aspmx.l.google.com.
example.com. 3600 IN MX 10 alt4.aspmx.l.google.com.
Priority 1 is tried first. If aspmx.l.google.com is unreachable, senders fall back to priority 5, then 10. This gives you redundancy — email keeps flowing even if one server is down.
How to Look Up MX Records
Method 1: DNS Lookup Tool (fastest)
Enter any domain in our DNS Lookup Tool. MX records appear in the "Mail & Email Security" section with priorities sorted from highest to lowest preference. You'll also see whether SPF and DMARC are configured — critical for email deliverability.
Method 2: Command line
# Using dig
dig example.com MX +short
# Output:
# 1 aspmx.l.google.com.
# 5 alt1.aspmx.l.google.com.
# 5 alt2.aspmx.l.google.com.
# Using nslookup
nslookup -type=MX example.com
Common Email Providers and Their MX Records
| Provider | MX Records |
|---|---|
| Google Workspace | aspmx.l.google.com (pri 1), alt1-4.aspmx.l.google.com |
| Microsoft 365 | *.mail.protection.outlook.com |
| Zoho Mail | mx.zoho.com, mx2.zoho.com, mx3.zoho.com |
| ProtonMail | mail.protonmail.ch, mailsec.protonmail.ch |
| iCloud Mail | mx1-6.mail.icloud.com |
If your MX records don't match your email provider, that's your problem.
Troubleshooting MX Issues
No MX records found
Your domain can't receive email at all. Senders get a bounce. Fix: add MX records pointing to your email provider's servers.
MX records point to the wrong server
Common after switching email providers. You changed to Google Workspace but your MX still points to your old host. Update the MX records and remove the old ones.
MX record points to an IP address
MX records must point to a hostname, not an IP. 10 192.168.1.1 is invalid. The hostname must have its own A record that resolves to the IP.
Email works but goes to spam
MX records are fine, but you're missing email authentication. Check your SPF and DMARC records — our DNS Lookup Tool flags these in the email security section.
Multiple MX records with the same priority
Valid and common. Senders pick randomly between equal-priority servers, distributing load. Google uses this with alt1 and alt2 both at priority 5.
Why MX Records Matter Beyond Email
MX records reveal a lot about a domain's infrastructure:
- Which email provider they use — Google, Microsoft, or self-hosted
- Whether they have redundancy — Multiple MX records mean failover capability
- Whether the domain accepts email at all — No MX = no inbound email
Security researchers and pentesters routinely check MX records to understand a target's email setup. If you're auditing your own domain, start with a full DNS check.
Recommended Resources
- Free DNS Lookup Tool — Check MX records and email security for any domain
- SPF, DKIM, and DMARC Guide — Complete email authentication setup
- DNS Record Types Explained — What every DNS record type does
- How to Check DNS Records — Three free lookup methods
Morten Pradsgaard is the founder of exit1.dev — the free uptime monitor for people who actually ship. He writes no-bullshit guides on monitoring, reliability, and building software that doesn't crumble under pressure.