How-To

How to check your DKIM record, even if you don't know your selector

Inboxlogy6 min readUpdated 2026-10-26

In short: To check DKIM, open a free DKIM Checker, enter your domain and your selector, and it looks up the public key at selector._domainkey.yourdomain.com. If you do not know your selector, the tool tries common ones (like google, selector1, default) or you can read it from a sent message's DKIM-Signature header.

When should you check DKIM?

Check DKIM after setting up a new sending service, when migrating providers, before a cold email campaign, or when DMARC reports show DKIM failing. Because DKIM uses selectors, re-check whenever you add a new tool, since each one publishes its own key.

How to find your DKIM selector

You need the selector to check DKIM. Three ways to find it:

  • From a sent email. Open the message's raw headers and find the DKIM-Signature line. The s= value is your selector.
  • From your provider. Google Workspace uses google; Microsoft 365 uses selector1 and selector2; many tools show it in their DNS setup page.
  • Let the tool try common ones. The checker tests popular selectors automatically if you are not sure.

How to check your DKIM record step by step

  1. Open the DKIM Checker. Go to the free Inboxlogy DKIM Checker.
  2. Enter your domain and selector. For example domain yourdomain.com, selector google.
  3. Click Check DKIM. The tool looks up selector._domainkey.yourdomain.com in live DNS.
  4. Read the result. It confirms whether a public key is published and valid, and flags if the record is missing or the key was revoked.

How to fix a missing or broken DKIM record

If no key is found, DKIM is not set up for that selector. Enable DKIM in your sending tool, which gives you a public key (or a CNAME) to publish in DNS. If you manage your own keys, generate a fresh 2048-bit keypair with the DKIM Generator, publish the public key, and keep the private key on your mail server. Then re-check.

Check your DKIM record now

Confirm your public key is published and valid. Don't know your selector? The tool tries common ones. Free and instant.

Open the DKIM Checker →All free tools

Frequently asked questions

What if I don't know my DKIM selector?
Read it from the DKIM-Signature header of an email you sent (the s= value), check your provider's DNS setup page, or let the DKIM Checker try common selectors like google, selector1 and default.
Why does my DKIM check say the key is revoked?
An empty public key (p= with no value) means the key was revoked or rotated out. This is normal for old selectors after a provider rotates keys. Check the current selector your mail actually signs with.
Does DKIM need SPF to work?
No, DKIM works independently of SPF. But for DMARC to pass, you need either SPF or DKIM to pass and align with your From domain. Running both is the safest setup.
Is the DKIM Checker free?
Yes. It runs in your browser using public DNS, costs nothing, and never asks for an account.