Email & DNS

Email Header Analyser

Inspect supplied email headers and the claimed delivery route.

Calculations run in your browser. The tool does not send your inputs to a server.

01Your inputs

Local workspace

Start with the sample below, or enter your own values.

Raw email headersThe sample is editable. Keep the input format consistent with the action you choose.

02Your result

Your result will appear here. Choose an action after checking your inputs.

A quick guide

How to use this tool

Check the example and the unit beside each input.
Enter your values and choose Analyse.
Review the result and assumptions, then copy what you need.

Reset example restores the starting values. Clear removes text and number inputs, returns choices to their first valid option, and removes the result.

Reference guide

Explanation and worked examples

Folded header lines are unfolded and repeated fields are preserved. Received lines are reversed into claimed oldest-to-newest order. Headers and authentication claims can be forged; trust only evidence within your receiving system boundary. Encoded words are shown as supplied.

Use in day-to-day IT work

Inspect a message route and preserve headers for a mail-delivery investigation.

Checks before applying the result

Copy raw headers from the receiving mailbox. The blank line separates headers from the body, so body text is ignored.
Locate the trusted receiving-server boundary before interpreting Received or Authentication-Results. This tool does not verify DKIM signatures, detect every forgery or probe mail servers.

New to the terminology?

SPF: Sender Policy Framework: authorises sending hosts for a domain used by SMTP.
MTA-STS: A published policy for authenticated TLS delivery to declared MX hosts.
TTL: How long a DNS answer may normally remain cached.

Keep exploring

How calculations work and where the models stop →