List-Unsubscribe checker
A free List-Unsubscribe checker: paste the raw source of any email and get an instant verdict on its unsubscribe headers - RFC 8058 one-click compliance, https and mailto URIs, and DKIM presence. Everything runs in your browser, so the message never leaves your device.
How do I get the raw source of an email?
- Gmail (web): open the email, click the three-dot menu in the top right, choose Show original, then Copy to clipboard and paste it above.
- Outlook (web): open the email, click the three-dot menu, choose View then View message source, and copy everything.
- Apple Mail: open the email, then View, Message, Raw Source. Copy the whole window.
- Thunderbird: open the email and press Ctrl+U (Cmd+U on Mac).
- Most desktop clients can also drag an email out as a .eml file - drop it straight onto the box above.
What this List-Unsubscribe checker tests
The verdict grades an email the way mailbox providers see it. Grade A means the message is one-click compliant: an https unsubscribe URI in the List-Unsubscribe header, a correct List-Unsubscribe-Post: List-Unsubscribe=One-Click header, and a DKIM signature on the message. Grade B means the header works but one-click is missing or incomplete. Grade C means only a mailto or insecure http route exists, and Grade F means there is no usable unsubscribe header at all.
Each failed check comes with the fix: the exact header to add, why https is required, and what the Post header value has to say. Senders use this before a campaign goes out; recipients use it to understand why an email does or does not show the native Unsubscribe button in Gmail or Outlook.
The Gmail and Yahoo one-click requirement
Since February 2024, Gmail and Yahoo require bulk senders (roughly 5,000+ messages a day to their users) to support RFC 8058 one-click unsubscribe and to honour requests within two days. Mail that fails the requirement gets throttled or lands in spam. The rules also require aligned authentication, which is why this tool checks for a DKIM signature whose domain lines up with the From address.
If you are a sender, run your next campaign template through the checker before it ships. If you are cleaning your own inbox, grade A senders are the ones ClearMyInbox can unsubscribe you from silently, with a single request and no web page in between.
Check one email here. Clean your whole inbox with ClearMyInbox.
ClearMyInbox scans Gmail, Outlook, Yahoo, or any IMAP inbox, finds every sender's unsubscribe route using this same analysis, and unsubscribes you in bulk. Free plan includes 3 scans a month.
Get started freeHow to read the header checks
- List-Unsubscribe present - the header exists. Without it, mailbox providers show no native unsubscribe button.
- Header format - URIs must be comma-separated and wrapped in angle brackets, per RFC 2369.
- HTTPS URI - one-click requires an https endpoint; http and mailto-only setups fail this check.
- One-click Post header - the value must be exactly
List-Unsubscribe=One-Click. - DKIM signature - RFC 8058 requires the headers to be covered by an aligned DKIM signature. This check is structural: it confirms presence and domain alignment without any DNS lookup, so the tool stays fully offline.
Frequently asked questions
What is the List-Unsubscribe header?
List-Unsubscribe is a hidden email header (defined in RFC 2369) that tells mailbox providers where a recipient can unsubscribe - an https URL, a mailto address, or both. Gmail, Outlook, and Yahoo use it to show their native unsubscribe button at the top of the message, separate from any link in the email body.
What is RFC 8058 one-click unsubscribe?
RFC 8058 adds a second header, List-Unsubscribe-Post: List-Unsubscribe=One-Click. When it is present alongside an https URL in List-Unsubscribe, the mailbox provider can unsubscribe the recipient with a single POST request - no web page, no confirmation step, no login. The message must also carry a valid DKIM signature covering those headers.
Why do Gmail and Yahoo require one-click unsubscribe?
Since February 2024, Gmail and Yahoo require senders of bulk marketing email to support one-click unsubscribe and to honour requests within two days. Senders that fail the requirement see their mail throttled or sent to spam, which is why deliverability teams test these headers before every campaign.
Does this tool send my email anywhere?
No. The whole analysis runs in your browser using JavaScript - the pasted email is never uploaded, stored, or sent over the network. The only thing transmitted is an anonymous usage ping to our own analytics (which tool ran and the verdict grade, never any part of your email), and our test suite enforces that nothing else leaves the page during analysis.
Why does my grade say the DKIM check is structural only?
Verifying a DKIM signature cryptographically requires fetching the sender’s public key from DNS, which would mean making network requests. This tool deliberately makes none, so it checks that a DKIM-Signature header exists and that its d= domain lines up with the From domain - which catches the common failures - but it does not validate the signature bytes.
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Prefer a guide? Our email cleanup guides cover unsubscribing and inbox zero step by step.