DKIM Selector Finder - Find Active DKIM Selectors for Any Domain
Automatically check the most common DKIM selectors for any domain. Finds active DKIM keys published in DNS without needing to know the selector name in advance.
What is a DKIM selector?
A DKIM selector is a label that identifies which DKIM key was used to sign an email. It appears in the s= tag of the DKIM-Signature header in every signed email.
The selector tells receiving mail servers where to look up the public key in DNS: at selector._domainkey.yourdomain.com.
Each email provider uses different selector names. Google Workspace uses google, Microsoft 365 uses selector1 and selector2, Mailchimp uses k1, and so on.
If you do not know which selector your domain uses, this tool scans the most common ones automatically.
Common DKIM selectors by provider
| Provider | Common selector(s) |
|---|---|
| Google Workspace | google |
| Microsoft 365 | selector1, selector2 |
| Mailchimp | k1, k2 |
| Mailgun | pic, mailo, mg |
| SendGrid | s1, s2 |
| Postmark | pm |
| Amazon SES | amazonses |
| Zoho Mail | zoho |
| ProtonMail | protonmail |
| Brevo (Sendinblue) | mail |
When to use the DKIM Selector Finder
- You do not know which selector your provider uses - scan and find it automatically.
- Auditing a domain - see all active DKIM keys to confirm only expected senders have keys published.
- After migrating email providers - verify old provider keys are removed and new ones are live.
- Debugging DKIM failures - confirm the selector exists in DNS before checking the key content.
FAQ
My DKIM selector was not found - does that mean DKIM is not set up?
Not necessarily. Your domain may use a custom selector name that is not in the common list. Check your email provider's admin panel for the DKIM selector they assigned, then use the DKIM Checker with that specific selector name.
I found more selectors than expected - is that a problem?
Multiple active DKIM selectors are normal if you use more than one sending service. Each service signs with its own selector and key. The concern is if you find a selector for a provider you no longer use - those old keys should be removed from DNS.
Can a domain have multiple DKIM selectors?
Yes. A domain can have as many DKIM selectors as needed - one per sending service is typical. Each selector is at a different DNS hostname, so there is no conflict between them.
What is the difference between DKIM selector and DKIM key?
The selector is the name that points to the DNS record. The key is the cryptographic public key stored in that DNS record. When a receiving server verifies a signed email, it uses the selector from the email header to find the DNS record, then uses the public key in that record to verify the signature.
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