Email header analyzer.
Paste the raw headers from any email and read the whole delivery story — the Received hops in order, the delay at each stop and the total transit time, plus the SPF, DKIM and DMARC verdicts. Parsing happens right here in your browser; nothing is uploaded.
What the headers tell you
Every email carries a stack of headers the mail servers add as it travels. Read together, they answer two practical questions:
- How did it get here, and how fast?
- The Received hops trace the exact path from the sender's server to the inbox. Timing the gaps between them shows where a message stalled — a slow hop is often greylisting or a backed-up queue, not a broken address.
- Was it actually authenticated?
- The SPF, DKIM and DMARC verdicts show whether the receiving server believed the message really came from its claimed domain. See the guide to SPF, DKIM and DMARC for what each check proves.
Using headers to debug deliverability
When a message lands in spam, the headers are the first place to look. A DKIM or DMARC failure, an unexpected relay in the Received chain, or a long stall between hops are all clues that point to a specific fix — and most of them trace back to authentication or list quality rather than the content itself. The rundown of why emails go to spam walks through the common causes and how the headers reveal them.
Email header analyzer — FAQ
Fix the addresses before they bounce
Headers explain a delivery after the fact — verification stops the bad ones first. Clean your list to remove invalid and dead addresses before you send; start free with 100 credits, no card required.