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MX Record Validator

Validate MX record lines for priority and host formatting—client-side.

Results

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Status
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Details
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Records
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Issues
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How to use this validator

  1. Paste MX records (priority host) line by line.
  2. Run validate to check numeric priority and host format.
  3. Fix non-numeric priorities or malformed hosts, then re-run.

Rules & checks

Requires priority then host per line.

Priority must be a non-negative number.

Host must look like a valid domain (letters, digits, dashes, and dots).

Runs fully client-side; no data stored.

Inputs explained

  • MX records

    Paste MX lines (priority then host), one per line. Format: '<priority> <host>'.

When to use it

  • QA MX records before DNS updates
  • Support teams checking customer DNS inputs
  • Templates for automated DNS generation

Common errors

  • Non-numeric priority
  • Missing host after priority
  • Host with invalid characters (underscores, spaces)

Tips

  • Use FQDNs (with dots) for mail hosts
  • Prefer multiple MX entries for redundancy
  • Keep priorities ascending; lower number = higher priority

Examples

Valid

  • 10 mail.example.com
  • 20 mail.backup.com

Invalid priority

  • abc mail.example.com -> flagged

Invalid host

  • 10 mail_example -> flagged

FAQs

Is this uploaded?
No. Validation runs locally and clears on refresh.

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