Free DKIM checker · Instant · No signup

DKIM Checker

Look up your DKIM record and public key. Domain Doctor probes common selectors, validates the key, and checks its length so your signed mail is trusted.

19 checks per scan Results in seconds Free, no signup

The tool

What the DKIM Checker checks

DKIM (DomainKeys Identified Mail) adds a cryptographic signature to your outgoing email. Receivers fetch your public key from DNS and verify the signature, proving the message really came from you and was not tampered with in transit.

DKIM keys live at selector._domainkey.yourdomain.com, and the selector varies by provider. Domain Doctor probes the common selectors (default, google, selector1/2, k1, and many more), validates the v=DKIM1; p= record, and checks the key length, 1024-bit keys are weak; 2048-bit is recommended.

How it works

Check your domain in three steps

1Enter your domainType any domain into the box above and start the free scan. No signup, no software.

2We inspect it liveDomain Doctor probes common DKIM selectors for your public key, in real time from our servers.

3Get a clear verdictYou get a plain-language result, the exact records we found, and a concrete fix if anything is wrong.

What to watch for

Common DKIM Checker problems

DKIM not set up for your sending provider
Using an uncommon selector we cannot auto-discover
Revoked key (empty p= value)
Weak 1024-bit key instead of 2048-bit
Key split incorrectly across DNS TXT chunks

VASTROX Email Security

Sign your mail with strong DKIM keys

We generate 2048-bit DKIM keys, publish them for every sending service, and rotate them on schedule.

2048-bit DKIM keys for every sender
Correct selector setup and DNS publishing
Scheduled key rotation

Set up DKIM Talk to VASTROX about email

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Questions

Frequently asked

What is a DKIM selector?

A selector names which key to use, so you can rotate keys. It forms the DNS name selector._domainkey.yourdomain.com. Your email provider tells you which selector to publish.

Why can’t the tool find my DKIM record?

DKIM only lives under the selector your provider uses. If you use a custom selector we do not probe, look it up in your provider’s settings and check that exact name.

What key length should DKIM use?

2048-bit RSA is the current recommendation. 1024-bit still works but is considered weak; Ed25519 keys are also valid.