Zero is listed under Email, Scheduling & Tasks, in the Productivity & Workflow category on Flocci AI Tools. Fully open-source (MIT license), self-hostable AI email client. It is free, with no paid plan attached, and it lives at 0.email.
Zero is listed as fully free — there is no paid tier attached to it in the catalog. That makes it one of the 115 entries on Flocci AI Tools with no upgrade path built in.
Zero does 3 things the catalog singles out: Fully open-source (mit license), self-hostable ai email client; ai agents/llms built into the mail workflow, not bolted on; 10.7k+ github stars, active 2025-2026 development.
Inbox Zero is the closest free alternative: it sits in the same Email, Scheduling & Tasks sub-category and is free tier + paid plans. Reclaim.ai, Shortwave and Taskade also start free. The full list is on the alternatives page.
See the full list →