DKIM checker - Folderly Lens

Check DKIM before unsigned mail weakens sender trust.

Paste sending domains and Lens opens the full estate scanner. The public scan checks authentication posture, blacklist exposure, and the DNS signals that decide whether each domain should be retired, fixed, or kept.

0 mailbox or sequencer access
DNS authentication context
K/R/K retire, fix, or keep verdict

Run the check

Open the full Lens scanner with verdicts and a copyable fix plan.

Enter at least one valid domain or IP.

Why DKIM matters

Signature trust

DKIM gives receiving systems a cryptographic signal that mail was authorized by the domain owner.

Selector drift

Cold-email estates often inherit stale selectors, missing keys, or vendor-specific signing gaps.

Not a solo signal

Lens treats DKIM as part of the broader authentication picture with SPF, DMARC, MX, and blacklist state.

How to act on the result

If DKIM is missing

Enable signing in the active sending platform and publish the correct selector records before scaling volume.

If selectors are unknown

Inventory every sender, confirm the selector each one uses, and remove stale tools from DNS.

If authentication is clean

Keep the domain only if DMARC, SPF, MX, and blacklist signals are also clean.

DKIM checker FAQ

Can Lens see every selector?

The free public scan uses the same estate workflow and the full collector can probe a wider selector set during the manual audit.

Does DKIM replace DMARC?

No. DKIM helps authenticate mail, while DMARC tells receivers what to do when authentication fails.

Do you need mailbox access?

No. Folderly Lens reads public DNS and external reputation signals only.