Where do I publish the DKIM record for Proton Mail?

You publish DKIM as a TXT record at selector._domainkey.yourdomain.com, where selector is the name given by Proton Mail.

How do I know if DKIM is working?

Send a message to a Gmail inbox and look at Show original. If DKIM shows PASS for your domain, the record is working.

Yes. Many providers support multiple selectors to rotate keys or support several sending systems.

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

Want to check your domain while following this guide?

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

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

Different dashboards label DNS fields differently. Always verify the published record using dig or a checker.
If records look right but still fail, it is usually caching, propagation delay, or a host name mismatch.
Proton Mail Settings → All settings → Custom domain → Authentication.

In Proton Mail, generate a DKIM key and note the selector. Providers often suggest something like protonmail1.

Proton Mail Settings → All settings → Custom domain → Authentication.

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

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

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.

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

Check SPF, DKIM, DMARC and List-Unsubscribe for your domain in seconds.