IP Subnet CalculatorHeader Analyzer
Make sense of headers without squinting at hundreds of lines of raw text — analyse email message headers to trace delivery and authentication, and audit a website's HTTP security headers.
Email Header Analyzer
Paste raw message headers to trace the delivery path, check SPF/DKIM/DMARC verdicts and alignment, read spam scores, and spot spoofing — without squinting at 200 lines of text.
Authentication & verdicts
Message summary
Delivery path
Hops run oldest → newest. The Delay column shows how long each server held the message — the hop with the big number is where a delivery delay happened.
HTTP Security Headers Scanner
Fetches a website and grades its HTTP security response headers — HSTS, Content-Security-Policy, X-Frame-Options, X-Content-Type-Options, Referrer-Policy and Permissions-Policy — and flags headers that leak software versions. Runs from this server (a public-vantage check); nothing is stored.