Email Headers Checker
Email headers contain the real authentication results: SPF, DKIM, DMARC, ARC and routing details. This page explains what to look for and links to the tools below.
Quick start
- Open an email in your mailbox and choose “View original” or “Show headers”.
- Find Authentication-Results and check SPF/DKIM/DMARC verdicts.
- Paste the headers into our tool to extract key signals.
Related DNS checks
Headers show results, DNS records define policy. Use these tools to verify DNS.
FAQ
Where do I find email headers?
Most mailboxes have “View original” or “Show headers” in message options.
Which header matters the most?
Start with Authentication-Results for SPF/DKIM/DMARC verdicts.
Why does SPF pass but DMARC fails?
DMARC requires alignment. SPF can pass for a different domain than the visible From.
Do headers replace DNS checks?
No. Headers show results, DNS controls policy and what should happen.
Is it safe to paste headers?
Headers can contain IDs. Avoid pasting full body content. Use test emails when possible.
What you can verify
- SPF: sender IP authorization
- DKIM: cryptographic signature validity
- DMARC: alignment and policy
- ARC: forwarding chain signals
- Routing: Received hops and delays
Open the tool
Paste raw headers to extract and summarize authentication signals.
Email Headers Checker