List-Unsubscribe Header Generator
Older sibling of the one-click builder. Produces a List-Unsubscribe header (without the POST extension) for legacy compatibility with older mail clients.
List-Unsubscribe: <mailto:unsubscribe@example.com>, <https://example.com/unsubscribe?id=abc123>
Made it. Now see what happens after you send.
Outsolvi tracks your email once it leaves your outbox: which opens were a person and which were a machine, who clicked, and who replied. Follow-ups stop on their own when someone answers. Outlook and Gmail, from $7/user/mo billed yearly.
Track your next sendBuilds the header from a mailto: address and an https: URL. Validates the formatting; List-Unsubscribe requires angle brackets and comma separation.
Any list send. Even where one-click isn't required, having a valid List-Unsubscribe header improves inbox placement and reduces 'mark as spam' clicks.
FAQ
Do I need both mailto and URL?+
Recommended. Different mail clients prefer different methods. Including both maximizes the chance the recipient's client renders a native unsubscribe button instead of relying on body-link unsubscribes.
Keep going
Articles, glossary entries, and other tools on the same topic.
Nate built Outsolvi after watching every email-tracking tool he had ever used lie to him about opens. Outsolvi grades every open as a person or a machine, in Outlook and Gmail, so the number on the dashboard is one a rep can actually act on.
We update these pages when the underlying mechanics change. new mailbox-provider rules, new tracker behavior, new measurement gaps. The dates above are real revisions, not auto-touches.