Inspect email Received headers in delivery order, compare hop timestamps and read Authentication-Results when investigating delays or authentication.
Inputs are processed in your browser. This tool does not send or store them on a server.
Copy headers from your mail client’s message source. Parsing ends at the first blank line before the body. Folded lines are joined to the preceding field.
Negative delays can result from server clock differences. Authentication results are pasted claims; this tool cannot establish the receiver’s trust boundary or revalidate SPF, DKIM or DMARC. It does not establish sender authenticity.
RFC 8601: Authentication-Results · SPF, DKIM and DMARC Checker
Yuru Tech Note explains the underlying formats and protocols with examples.