Privacy-first email tool
Email Header Inspector
Paste email headers and review sender, reply-to, authentication, and routing signals.
Your pasted headers stay in your browser. CheckLink does not receive or store the email header text.
Header summary
Header signals can be forged, missing, or modified. Use this as context, not proof.
From
Not found
Reply-To
Not found
Return-Path
Not found
Sender
Not found
Message-ID
Not found
Subject
Not found
Date
Not found
Authentication-Results
Not found
SPF
Not found
DKIM
Not found
DMARC
Not found
Received header count
0
Signals found
Authentication-Results header was not found.
FAQ
What are email headers?
Headers are metadata that can show sender fields, routing information, and authentication results.
Does CheckLink upload my headers?
No. This inspector parses pasted header text locally in your browser.
What are SPF, DKIM, and DMARC?
They are email authentication mechanisms that help receiving systems evaluate whether a message aligns with a domain's sending rules.
Does a failed check prove phishing?
No. It is a caution signal that needs context and may deserve manual review.