Build the List-Unsubscribe headers (one-click unsubscribe)
When people can unsubscribe with one click, they do not press “report spam” instead. That difference decides whether your next mailing reaches the inbox at all.
- Runs entirely in your browser
- Works offline
- No upload
- No sign-up
- No watermark
Loading the tool…
How it works
- Enter your one-click unsubscribe web address (URL). It must be different for each subscriber, usually with a code (token) at the end.
- If you also have an unsubscribe email address (mailto), add it as a backup.
- Copy both lines into your sending system, or give them to your mail provider. They must be inside the DKIM signature (the part of the mail your server signs).
Why nothing is uploaded
Every operation on this page is done by code running inside your browser tab, using the same engine that renders web pages. The file is read from disk into your tab’s memory, transformed there, and written back out as a download. It is never sent anywhere — not to us, not to a third party.
Verify it yourself
- Open your browser’s developer tools (F12) and select the Network tab.
- Load your file and run the tool.
- The only requests you will see fetch the tool’s own code — and, for a few heavy tools, their open-source engine from a public CDN — plus one small page-view ping to loreatec.jp (page address and title, nothing more). None of them carry your file.
Frequently asked questions
What exactly do Gmail and Yahoo require?
Since February 2024, anyone sending roughly 5,000 messages a day or more to their users must offer one-click unsubscribe in the header, act on it within two days, keep spam complaints below 0.3 % (they say aim for 0.1 %), and prove the sender with SPF, DKIM and DMARC (three DNS records for your domain). The header alone is not enough, it is one requirement of several, but it is the cheapest to get right.
Why must my unsubscribe address accept POST?
Because a normal link (GET) is opened by every security scanner and preview tool that touches the mail, and people would be unsubscribed without asking. The standard (RFC 8058) uses a POST request with the text List-Unsubscribe=One-Click, which scanners never send. Your address must act on that request directly: no login page, no confirmation screen, no session.
Can I keep only the mailto: version?
It still works and is worth keeping as a backup, but on its own it does not meet the 2024 rules, and Gmail will not show its unsubscribe button for it. It also makes the person wait for a mail round trip before they are removed.
Do I still need a link in the message body?
Yes. The header is in addition to the visible link, never instead of it — and in Japan 特定電子メール法 requires a way to opt out that the recipient can actually see, as does CAN-SPAM in the United States.