Free tools. Clear limits.

Email investigation tools.

Choose a starting point below. These tools run in your browser, with no mailbox connection or upload.

Email diagnostic

Three questions. An ordered next step for your symptom and sending route.

Start the diagnostic

Header explainer

Read recorded authentication results. No upload, DNS lookup or signature verification.

Read a header

IT handoff builder

Put the symptom and evidence into a brief. Copy, download or print it.

Build a handoff

These tools help you investigate. They don’t measure inbox placement.

The diagnostic routes you to guidance. The header explainer reads recorded results without verifying signatures or querying DNS. For an actual placement check, send a controlled message to a testing service. See how the different tests work.

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Need to see where a test message lands?

GlockApps can show placement in its test mailboxes. Use your actual sending route and read the results by provider. It cannot guarantee placement with your candidates or clients.

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