Why does a domain have multiple MX records?

It is completely normal for a domain to publish multiple MX (Mail Exchange) records. This is typically done for redundancy, load distribution, and provider-specific architecture.

Multiple MX records do not indicate a misconfiguration by default. In fact, most modern email platforms rely on multiple entries as part of their design.

You can inspect a domain's MX setup with the DNS Pro MX Lookup tool.

For comparison, you can also use MXToolbox: https://mxtoolbox.com/MXLookup.aspx

Each MX record includes a preference (priority) value. Lower numbers are preferred and will be attempted first by sending mail servers.

example.com. 3600 IN MX 0 mail1.example.com.
example.com. 3600 IN MX 10 mail2.example.com.

In this example, mail1.example.com (priority 0) will be tried before mail2.example.com (priority 10).

If the primary host is unavailable, the sending server will fall back to the next highest priority.

Email providers commonly publish multiple MX records to support resilient and scalable infrastructure.

• Redundancy → ensures mail delivery continues if one host fails
• Load distribution → spreads traffic across multiple servers
• Geographic distribution → routes mail to the nearest or optimal region
• Platform design → reflects internal architecture of large providers

For example, platforms like Microsoft 365 or Google Workspace typically use multiple MX records as part of their normal configuration.

Some domains publish multiple MX records with the same priority value.

example.com. 3600 IN MX 10 mail1.example.com.
example.com. 3600 IN MX 10 mail2.example.com.

In this scenario, sending servers may choose between them, effectively balancing traffic across both hosts.

• MX priorities follow a logical order (lower = preferred)
• All MX targets belong to the expected email provider
• Each MX hostname resolves to valid A/AAAA records
• There are no legacy MX records from previous providers
• There are no conflicting providers configured simultaneously

If you're unsure about record structure, review: /articles/what-is-dns

• Leaving old MX records in place after a migration
• Mixing multiple email providers unintentionally
• Assuming each MX record should map to only one IP
• Misinterpreting multiple records as duplication instead of redundancy

# Query MX records
dig MX example.com

# Alternative
nslookup -type=mx example.com

If you want to validate this topic in practice, these DNS Pro tools are the fastest next step.

• MX Lookup
• Email Provider Setup Checker
• Email Security Check