How to set up DKIM on Mailgun

Step by step DKIM setup for Mailgun: complete instructions, examples, verification commands, and common pitfalls.

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This is a reference guide for configuring DKIM on Mailgun. Use it while editing DNS or when troubleshooting deliverability.

Tip: Here’s a reliable, copy-pasteable way to set up DKIM using Mailgun. Then verify everything with the InboxGreen Free Checker.

Provider-specific notes for Mailgun

  • Mailgun provides specific TXT and CNAME values unique to your domain. Copy them exactly from the Mailgun DNS Records panel - do not guess the values.
  • Mailgun DKIM can use either TXT or CNAME depending on your plan. Check the DNS Records tab in your Mailgun domain settings for the correct format.
  • Mailgun → Sending → Domains → Domain DNS Records.

What you’ll need

  • Access to Mailgun to generate a DKIM key and selector.
  • DNS provider access to publish a TXT record at selector._domainkey.

Generate your DKIM key

In Mailgun, generate a DKIM key and note the selector. Providers often suggest something like mailo or pic (check Mailgun DNS records panel).

Mailgun → Sending → Domains → Domain DNS Records.

Publish the record

  1. Create a TXT record at host selector._domainkey (replace selector with your actual selector name).
  2. Paste the full value starting with v=DKIM1; k=rsa; p= and save.
  3. Wait for DNS propagation.

Verify DKIM

  • Send a test email to a Gmail address and use “Show original” to confirm “DKIM: PASS”.
  • Or run: 
    dig TXT selector._domainkey.yourdomain.com +short

Common mistakes

  • Using the wrong host so the record becomes selector._domainkey.yourdomain.com.yourdomain.com.
  • Breaking the value by wrapping or truncating the TXT string.
  • Publishing a record for the wrong selector and then validating on another.

Related for Mailgun

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Pro tip: Turn on InboxGreen Monitoring to check these records daily and get alerts if something breaks.

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