Email Header Analyzer
Parse and analyze raw email headers to trace delivery path.
Paste the full email headers from your email client. They include routing, authentication, and delivery information.
What Are Email Headers?
Email headers are metadata that travel with every email message. While most people only see the "From," "To," and "Subject" lines, the full headers contain a detailed record of every server the message passed through on its way to your inbox. Each mail server along the route adds a "Received" header, creating a chain that traces the email's delivery path from origin to destination. Headers also contain authentication results, spam scores, and technical details about how the message was processed.
Reading the Delivery Path
The delivery path is recorded in Received headers, which are read from bottom to top — the bottom-most "Received" line is the originating server, and the top-most is the last server before your inbox. Each hop includes the server's hostname or IP, a timestamp, and sometimes protocol details (ESMTP, TLS). By comparing timestamps between consecutive hops, you can identify where delays occurred. A gap of minutes or hours between two hops often points to spam filtering, greylisting, or server queue congestion.
Authentication Headers
Modern email authentication uses three main mechanisms: SPF (Sender Policy Framework) verifies that the sending IP is authorized for the domain, DKIM (DomainKeys Identified Mail) verifies a cryptographic signature on the message, and DMARC (Domain-based Message Authentication, Reporting & Conformance) ties SPF and DKIM together with a policy for handling failures. Authentication results are recorded in Authentication-Results headers. A "pass" for all three is ideal; failures can explain why messages land in spam or get rejected.
Common Use Cases
Email headers help diagnose delivery problems (why an email was delayed or never arrived), investigate phishing attempts (verifying the actual origin vs. the displayed "From" address), troubleshoot SPF/DKIM/DMARC failures, and understand how spam filters scored a message. This tool parses all of this automatically, so you don't have to read through dozens of cryptic header lines manually.