Free tool · 100% in-browser

List-Unsubscribe & one-click generator

Build the List-Unsubscribe and List-Unsubscribe-Post headers that Gmail, Yahoo and Microsoft require from bulk senders in 2026. Enter your HTTPS unsubscribe endpoint (and an optional mailto) to get one-click-ready headers, validated as you type. Generated in your browser.

HTTPS unsubscribe URL (one-click POST endpoint)

Mailto unsubscribe (optional) Mailto subject (optional)

Compliance

Headers (add both to every message)

These are per-message headers set by your sending app (MailWizz and most ESPs add them automatically). PowerMTA passes them through. Make the URL unique per recipient and honor unsubscribes within a couple of days.

List-Unsubscribe FAQ

Why do I need a List-Unsubscribe header in 2026?+

Gmail, Yahoo and Microsoft require bulk senders to support one-click unsubscribe. That means a List-Unsubscribe header with an HTTPS URL plus a List-Unsubscribe-Post header. Without it, your mail is more likely to be filtered, and you can fall out of compliance with the bulk-sender rules.

What is one-click unsubscribe (RFC 8058)?+

It lets the mailbox provider show a native Unsubscribe link that, when clicked, sends a single POST request to your URL — no landing page, no login. It requires an HTTPS URL in List-Unsubscribe and the header List-Unsubscribe-Post: List-Unsubscribe=One-Click. A mailto-only header is the older, non-one-click form.

Where do these headers go — in PowerMTA?+

They're per-message headers set by your sending application (MailWizz and most ESPs add them automatically), not a PowerMTA config setting. PowerMTA passes them through. If you generate messages yourself, add the two headers to each message; ideally the unsubscribe URL is unique per recipient.

Does one-click replace the unsubscribe link in my email body?+

No — keep a visible unsubscribe link in the body too. One-click is an additional, header-based mechanism the mailbox UI uses. You need both: the in-body link and the List-Unsubscribe headers, and you must honor unsubscribes promptly (within a couple of days).