If Workspace mail does not authenticate with DKIM, verify the selected domain, published selector key, and Gmail’s signing state. A TXT record existing somewhere in DNS does not prove the actual outgoing message was signed correctly.
Check the intended domain and selector
In the Admin console’s Authenticate email settings, inspect the domain used by the sender. Compare the generated DNS host name and public-key value with the record published by the DNS provider.
Watch for a domain suffix added twice, a truncated key, or an old selector already used by another service. Google’s setup supports a different selector when necessary. Do not delete a working third-party key without identifying the mail that depends on it.
Complete the signing setup
After publishing the correct key, use Start authentication in the appropriate Workspace domain settings. Google’s current guide notes that new Gmail activations can require 24–72 hours before key generation is available, and DNS changes can take up to 48 hours to start working.
A status message asking for DNS updates can persist while changes propagate. Check the actual published record rather than repeatedly generating new keys, which changes the values you are trying to verify.
Inspect a recipient-side test
Send a harmless message to another Gmail or Workspace user and inspect the full headers there. Google says a message sent only to yourself is not a suitable DKIM verification test. Look for the DKIM result, signing domain, and selector.
If the signature is present but fails, investigate changes made by gateways, footers, or other processing after signing. If it is absent, inspect the sending route and signing configuration. Do not weaken DMARC or disable filtering globally to hide a DKIM fault. Preserve the original DNS state and test evidence before a deliberate key rotation, and keep private keys out of support screenshots or public posts.
Browse Gmail & Google Account help
References
- Set up DKIM | Security & data protection | Google Workspace Help
- Troubleshoot DKIM issues | Security & data protection | Google Workspace Help
Reviewed against the linked product guidance, standards, and identified vendor or public-authority guidance on October 29, 2026. Available options and screen labels can vary by account, device, region, and organization policy.