How to find my DKIM selector?

Your DKIM selector identifies which DKIM key to use for verification. Each email provider uses different selectors.

Method 1: Check your email provider documentation

| Provider | Default selector(s) | |----------|-------------------| | Google Workspace | google | | Microsoft 365 | selector1, selector2 | | Mailchimp | k1 | | SendGrid | s1, s2 | | Amazon SES | Random (check SES console) | | Postmark | 20240101 (date-based) | | Mailgun | smtp, k1 |

Method 2: Check email headers

1. Send an email to yourself
2. View the full email headers/source
3. Look for DKIM-Signature: header
4. Find the s= parameter — that's your selector

Example:

DKIM-Signature: v=1; a=rsa-sha256; d=example.com; s=google;

Selector = google

Method 3: DNS lookup If you know the selector, verify the DKIM key exists:

dig TXT google._domainkey.example.com

Method 4: Use IntoDNS.ai Scan your domain at https://intodns.ai — the DKIM section automatically discovers and validates common selectors for your domain.

Multiple selectors: You can have multiple DKIM selectors active simultaneously. This is normal when using multiple email services (e.g., Google for inbox + SendGrid for marketing).