DKIM cryptographically signs your mail. Enter the domain and the selector (Google Workspace uses “google”, Microsoft 365 uses “selector1” and “selector2”).
Privacy: this tool runs entirely in your browser. When you click Check, one DNS query for the domain you typed goes to Cloudflare's public DNS resolver (Google's as fallback). Nothing is stored, logged or sent to GrowthPal.
DKIM adds a cryptographic signature to every message you send; the public key lives in your DNS at selector._domainkey.yourdomain. Receivers verify the signature to confirm the mail really came from you and wasn't altered. Together with SPF and DMARC it forms the authentication trio every inbox now expects, and every cold email sending domain needs all three before the first send.
Tools check the plumbing. The message is what your market answers. Get your TAM mapped, your ICP broken down and 5 angles written for your buyers, free.