DNS & Email Trust
medium Severity
Free Check

DKIM (DomainKeys Identified Mail) Selectors

Checks for cryptographic DKIM public keys used to digitally sign outbound emails and prevent tampering in transit.

Test Your Website for DKIM (DomainKeys Identified Mail) Selectors

Run this check along with 90+ automated tests across your domain.

Why It Matters

DKIM provides cryptographic proof that the email was actually sent by the domain owner and was not modified in transit.

How We Check This

We test common DKIM selectors (default, google, k1, s1, mailgun) for valid v=DKIM1 public keys.

How to Fix & Implement

Copy-paste configuration blocks tailored for your web server or edge proxy.

nginx snippet
# Configure selector._domainkey.yourdomain.com TXT in DNS:
k=rsa; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQ...

Frequently Asked Questions

What is a DKIM selector?

A selector allows a domain to maintain multiple public keys for different email services (e.g. Google Workspace vs SendGrid).