DNS Lookup: MX Records

Our MX Lookup tool helps you check the major MX records of a domain name.


About DNS MX Lookup

What does this tool do?

Our DNS MX Lookup tool examines Mail Exchange (MX) records for any domain name, revealing which mail servers are responsible for receiving email messages. It provides comprehensive DNS information including A, AAAA, NS, CNAME, and MX records with their respective priorities and TTL values.

Why is this useful?

MX lookups are essential for email troubleshooting, server configuration, and understanding email delivery paths. They help diagnose email delivery issues, verify mail server configurations, and ensure proper email routing for domain administrators and IT professionals.

Who uses this tool?

  • Email administrators - Configure and troubleshoot mail server settings
  • IT professionals - Diagnose email delivery problems and verify DNS configurations
  • Web developers - Set up contact forms and verify email functionality
  • System administrators - Monitor domain DNS health and email infrastructure
  • Security analysts - Investigate email-based threats and verify legitimate servers

How to perform an MX lookup

  1. Enter a domain name in the input field (with or without www prefix)
  2. The tool automatically removes http:// or https:// if included
  3. Click "Lookup" to query the DNS servers
  4. Review all DNS record types returned, focusing on MX records for email
  5. Check priority values to understand mail server fallback order

Example

Looking up google.com shows multiple MX records with different priorities (5, 10, 20, etc.), indicating Google's redundant mail server infrastructure for reliable email delivery.

Understanding your results

MX Records (Mail Exchange)
Specify mail servers that receive email for the domain, with priority values indicating preference order.
A Records
Map domain names to IPv4 addresses, showing where the domain's web services are hosted.
AAAA Records
Map domain names to IPv6 addresses for modern internet protocol support.
NS Records (Name Servers)
Identify the authoritative DNS servers responsible for the domain's DNS resolution.
CNAME Records
Create aliases that point one domain name to another, useful for subdomain management.
TTL (Time To Live)
Indicates how long DNS resolvers should cache the record before requesting fresh data.

What good MX records look like

  • Multiple MX records: Redundancy with different priority values
  • Proper priorities: Lower numbers (5, 10) for primary servers, higher for backups
  • Valid hostnames: Mail servers with proper domain names
  • Reasonable TTL: Usually 300-3600 seconds for timely updates

Common issues to watch for

  • No MX records: Domain cannot receive email
  • Single MX record: No redundancy if mail server fails
  • Incorrect priorities: All servers with same priority cause round-robin
  • Invalid targets: MX records pointing to non-existent servers

Important notes

  • MX records only show which servers can receive email, not send it
  • Some domains may use third-party email services (Google Workspace, Office 365)
  • DNS propagation can take time after changes are made
  • Actual email delivery depends on server configuration, not just DNS records

Common use cases

Email Troubleshooting

Diagnose why emails aren't being received by checking if MX records are properly configured and pointing to working mail servers.

Server Migration

Verify DNS changes during email server migrations to ensure continuity of email service and proper failover configuration.

Security Analysis

Investigate suspicious emails by checking the sender domain's legitimate mail servers and comparing with email headers.

Domain Configuration

Set up new domains or verify existing configurations to ensure proper email delivery and backup server redundancy.

Understanding MX priorities

MX record priorities work like rankings - lower numbers have higher priority. If the primary server (priority 10) is unavailable, email will be delivered to the backup server (priority 20). This provides redundancy and ensures reliable email delivery even during server maintenance or outages.

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