Inbox Zero

Inbox Zero is an open-source AI email assistant that works with Gmail and Outlook. It labels and archives messages, drafts voice-matched replies, follows up on unanswered threads, summarizes inbox activity, blocks cold email, handles bulk cleanup, and runs custom rules written in plain English. Its assistant can also use calendar and CRM context, file attachments, and operate through the web, Slack, or Telegram. The hosted service has a trial, while technical users can self-host the open-source application.