Nextbox
Nextbox is an email client that transforms crowded inboxes into a readable feed of cards, automatically separating real conversations into a DMs tab while keeping everything else one tap away. It runs entirely on-device, using your phone's built-in language model for AI-powered reply suggestions and summaries, so your mail never touches external servers. The app works with Gmail, Outlook, Fastmail, and any IMAP account, and blocks tracking images by default.
- Artificial Intelligence
- Consumer Electronics
- Software Only
Funding
Founders
Product
Problem
Traditional email clients present messages as a flat, chronological list, forcing users to wade through newsletters, receipts, and notifications to find real conversations. This buries active threads, wastes time, and creates a cluttered, stressful experience that fails to distinguish between important personal correspondence and bulk mail.
Solution
Nextbox reimagines the inbox as a feed of readable cards, with a dedicated DMs tab that automatically surfaces genuine back-and-forth conversations where at least two people have written. The app uses on-device AI, powered by the operating system's built-in language model, to privately suggest replies, summarize long threads, and highlight what likely needs attention. All processing happens locally on the user's device, ensuring message content, attachments, and search queries never touch a Nextbox server. Priority is a visible, correctable label rather than a hidden filter, and the complete, newest-first All Mail view remains one tap away at all times.
Target Audience
Primary users are privacy-conscious individuals who rely heavily on email for both personal and professional communication and are frustrated by cluttered inboxes, as well as power users who want AI assistance without compromising data privacy.
Features
- Feed-based interface displaying new mail as readable cards with fast, reversible actions
- Automatic DMs tab that separates real conversations from newsletters and notifications
- On-device AI using the OS-level language model for reply suggestions, thread summaries, and priority detection
- Complete privacy architecture with no server-side mail processing; content never leaves the device
- Tracking images blocked by default and links showing their real destination before clicking
- Works with Gmail, Outlook, Fastmail, and any IMAP account
- Cross-platform availability on iOS, macOS, Windows, and Linux with a shared on-device architecture
- No ads in paid tiers; inbox is never used as an advertising surface