DNS guide
DKIM Record Setup Guide
A DKIM record publishes your public signing key in DNS. Mail servers use it to verify that your emails haven't been tampered with. Here's how to add it correctly and avoid the common truncation mistake.
What a DKIM record looks like
Format: Name: [selector]._domainkey.yourdomain.com · Type: TXT · Value: v=DKIM1; k=rsa; p=[public key]
The truncation trap
DKIM public keys are long. Some DNS providers split them incorrectly. The full key must be in one record. If it's split wrong, DKIM verification fails silently.
Check DKIM selectors and strength
Open DNS Preflight →Step by step
FAQ
What is a DKIM record?
A TXT record that publishes your DKIM public key. Mail servers use it to verify your email signatures.
Where does the DKIM record go in DNS?
At [selector]._domainkey.yourdomain.com — for example google._domainkey.yourdomain.com for Google Workspace.
What key size should I use?
2048-bit minimum. 1024-bit is weak and should be rotated immediately. DNS Preflight shows your key strength.
Why does my DKIM record look wrong after adding it?
Probably truncated by your DNS provider. DKIM keys are long — check that the full p= value is preserved in the record.
How do I verify my DKIM record works?
Run DNS Preflight — it checks 14 common selectors and shows key strength for each one found.