Analyze email headers

Parse a raw email header block and report what the receiving path concluded: the SPF, DKIM and DMARC verdicts each hop recorded, whether those domains align with the From domain, the DKIM signatures and ARC chain present, and the delivery hops with the delay at each. With include_dns_validation left on, the From domain's SPF, DMARC and DKIM records are also read from live DNS so a verdict can be checked against what is published now. Callable with an API key or a dashboard session. The browser tool reaches this same endpoint with a captcha token instead, which is why you may see it called without credentials; a captcha is not something an API client can produce, so it is not part of this contract. The request body is snake_case, but the analysis in the response keeps camelCase field names (authenticationResults, receivedHops, dnsValidation) rather than the API-wide convention.