About This Launch
Mailbox Insights Email Header Analyzer is a free tool for anyone debugging email delivery. Paste raw headers and see routing hops and SPF, DKIM and DMARC results explained without jargon. The checks run in code; an LLM only turns the technical output into plain English. No account, and pasted headers are not stored.
Why I Built This
Raw email headers are hard to read, and most people debugging delivery problems just want to know what went wrong. I run Mailbox Insights, an Outlook and Microsoft 365 blog, and built this so anyone can paste headers and get a clear, plain-English explanation of routing and authentication, with no sign-up.
Launch Details
CategoryDeveloper Tools
StageLive
ListedOctober 16, 2026