Email Header & Latency Analyzer
Paste raw headers from any email message to inspect authentication results (SPF, DKIM, DMARC), trace MTA routing hops, and identify relay delays. Evaluated 100% locally in your browser.
How to Find Raw Email Headers
Email clients hide technical routing headers by default. Here is how to view raw headers in common email clients:
Gmail / Google Workspace
Open the email message, click the three dots (⋮) in the top-right corner of the email pane, and select “Show original”. Click “Copy to clipboard”.
Microsoft Outlook / 365
Open the email in a separate window, go to File → Properties. Look for the “Internet headers” box at the bottom and copy the text.
Apple Mail (macOS)
Select the message in your inbox, click View → Message → Raw Source(or press ⌥⌘U). Copy the entire header block above the message body.
Why Email Headers Matter for Deliverability
Every email sent across the Internet traverses multiple Mail Transfer Agents (MTAs). Each relay appends a Received: header recording the sending IP, receiving hostname, timestamp, and TLS encryption cipher. By inspecting these hops chronologically, engineers can identify exactly where message delays occur and whether spam filters or greylisting delayed delivery.
Additionally, mailbox providers like Google and Yahoo mandate strict cryptographic alignment. The Authentication-Results header summarizes whether SPF passed for the envelope sender and whether DKIM cryptographic signatures match the visible From: header domain.