Email Header Parser
Extracts the SMTP routing chain from Received: headers and displays each hop with its timestamp and server. Also shows From, To, Subject, Date, Message-ID, SPF/DKIM result, and any spam score headers (X-Spam-Score, X-Spam-Status).
How to get email headers
- Gmail: open the email → More (⋮) → Show original
- Outlook: open the email → File → Properties → Internet headers
- Apple Mail: open the email → View → Message → All Headers
- Yahoo Mail: open the email → More → View Raw Message
What the headers tell you
- Received: chain: the sequence of servers that handled the email, from originating to delivering; read from bottom to top for chronological order
- SPF (Sender Policy Framework): verifies the sending server is authorized for the sender domain
- DKIM (DomainKeys Identified Mail): a cryptographic signature that verifies the email was not modified in transit
- DMARC: a policy that tells receiving servers what to do when SPF or DKIM fails
- X-Spam-Score: the spam score assigned by the receiving server's spam filter
Diagnosing email delivery problems
If an email is not arriving, the Received: chain shows exactly where it stopped. Each hop has a timestamp, a large gap between two hops indicates a server delay.