Header Tool

Email Header analyzer

Paste your raw email header; the sender, recipient, traversed servers, delays and SPF/DKIM/DMARC results will be parsed automatically. The analysis runs entirely in your browser — your data is never sent to any server.

Gmail: ⋮ → "Show original"  ·  Outlook: File → Properties → Internet headers  ·  Apple Mail: View → Message → All Headers
About

What does an email header tell us?

Every email carries a "header" block alongside its visible content. This block contains the servers the message traversed, who sent it, and authentication results (SPF, DKIM, DMARC).

By analyzing the header you can identify delivery problems (e.g. why the message went to spam), latency hotspots, and spoofed senders. Each Received: line is a hop, and the message progresses bottom-up.

What This Tool Reveals

  • Sender / Recipient

    From, To, Reply-To and Return-Path lines are parsed.

  • Hop Chain

    Received lines are ordered, and per-hop latency is computed.

  • Auth Results

    SPF, DKIM, DMARC pass/fail status is shown with badges.

  • Total Latency

    See total delivery time and the slow hops along the path.