emailmetry
All free tools

Check your DKIM signing key.

Look up the public key your email provider publishes and check whether its settings need attention.

Free. No account required.

Your provider supplies this name. You can also find it beside s= in an email’s DKIM-Signature header.

Checks public DNS using Google Public DNS. Google receives the queried names and your IP address. Nothing is changed. How your data is handled.