Run a Live DKIM Verification
The message must be sent from the same address entered here so the code and sender match.
Generate a unique subject line tied to your email address.
Send an email to the verification inbox with the code as the exact subject.
We verify live DKIM, SPF, DMARC, and report the detected key size when available.
Why a Live DKIM Test Matters
DNS records can look correct while outbound email still fails authentication. This test confirms what actually happened on a delivered message.
Validates Real Mail Flow
We inspect a message that was actually sent, received, and evaluated by mail systems instead of relying only on record lookups.
Shows Key Strength
When the selector can be matched in DNS, the result includes the detected DKIM key size so weak keys stand out immediately.
Correlates SPF and DMARC
You also see whether SPF and DMARC passed on the same message, which helps isolate alignment issues and delivery risk.
How to Use DKIM Deep Dive
The process takes less than two minutes when your email app is ready.
Best Results
- Use the same business email address for the request and the test message.
- Keep the subject exactly as generated so the request can be matched.
- Send a simple blank email if you want the fastest verification.
- Wait a few seconds, then refresh if the status has not updated yet.
Common Failure Causes
- The email was sent from a different address than the one entered on the form.
- The sending platform is not applying DKIM signing consistently.
- A selector exists in DNS but the mail platform is using another selector.
- SPF or DMARC alignment settings are incomplete for the service sending mail.
Frequently Asked Questions
Answers for teams validating Microsoft 365, Google Workspace, SMTP relays, and third-party senders.
Does this replace a DNS-only mail security check?
No. DNS analysis tells you what records exist. DKIM Deep Dive confirms whether a live outbound message actually passed authentication during delivery.
Why can DKIM fail even if a DKIM record exists?
The sending service may not be signing mail, may be using the wrong selector, or may be signing with a different domain than expected. A live test exposes that gap.
Will I receive the results by email too?
Yes. Once the message is processed, we email the same DKIM, SPF, and DMARC result summary back to the address that started the test.
What if I need help fixing a failed result?
Use the result as the starting point, then review the DNS and provider sections below. If you need help implementing changes safely, NTS can assist with remediation.