Inbox Zero

Inbox Zero is an email client and AI email assistant for Gmail, Google Workspace and Outlook accounts. The email app runs on the web, on Mac and Windows desktops and as a native iPhone app, and is free to use. The web and desktop client is open source under the AGPL license, while the iPhone app is separate and not open source. Keyboard shortcuts and a command search handle navigation, and AI sorts incoming mail and drafts replies in the user's own style.

AI labels each email as it arrives and splits the inbox into tabs such as To Reply, Newsletter and Calendar. Drafts are written only for emails that need a reply. Several Gmail and Outlook accounts can sit in one inbox, and teammates can be pulled into a thread with comments that are never sent as email. Slack alerts tell users when an email needs them, and the Slack assistant accepts commands such as /summary, /cleanup and /draftreply.

The email app is free. AI plans, listed per user per month in USD in the comparison table, are Starter at $20/mo, Plus at $35/mo and Professional at $50/mo, each with a 7-day free trial. The page states that annual billing saves up to 20% on any plan. Enterprise buyers who need SSO, SCIM, on-premise deployment or a dedicated account manager are directed to sales. Payment is by major credit card through Stripe, and refunds are available within 14 days of upgrading.

Before buying, note that the AI features sit behind paid plans, and the Plus plan adds 2 email accounts per user, the AI meeting notetaker, Slack and app integrations such as Notion and Stripe. The Microsoft Teams integration is marked Coming Soon. The vendor states that it is SOC 2 Type 2 certified, that user data is not used for AI training, and that self-hosting is possible. Prices on the pages are in dollars.