What is Quartz?

Quartz is a Mac-native email client that transforms Gmail into a focused inbox. It uses on-device AI to automatically sort every message by importance, learning what matters to you over time. When you reply, Quartz drafts responses in your own voice—your cadence, phrasing, and warmth. Crucially, all AI processing runs locally on your Mac, so your email stays end-to-end encrypted and is never shared with any AI provider.

Who it's for

• Busy professionals who receive hundreds of emails daily and need a system that surfaces only what truly matters.
• Privacy-conscious users who want AI-powered email sorting and drafting without uploading their messages to third-party servers.
• Gmail power users on Mac who want a smarter inbox that adapts to their personal communication style over time.

Key features

Importance-based sorting

Quartz auto-categorizes every incoming message by importance—defined by you and learned over time. Important mail gets the space it deserves, while FYI, Icebox, and Noise items collapse out of sight. Your inbox stays scannable and focused.

On-device AI

The model that sorts your inbox and drafts replies runs entirely on your Mac (Apple Silicon required). Classification and drafting happen locally, so your mail is never uploaded to any server. Quartz has no servers to read your mail.

End-to-end encryption

Your mail is encrypted on your device with keys only you hold. Quartz is CASA Tier 2 certified—independently audited under Google's Cloud Application Security Assessment—so your privacy is verified, not just promised.

Replies in your voice

Give Quartz a few bullet points about your style. It learns how you write, understands your relationship with each sender, and picks up thread context. Drafts come back in your natural cadence and phrasing—no generic LLM tone.

What stands out

"Your emails stay private, never shared with AI providers."

This is the core differentiator: Quartz runs all AI processing locally on your Mac, so your email never touches an external server. Most AI email tools upload your messages to train models or generate replies—Quartz does none of that. Combined with end-to-end encryption and independent CASA Tier 2 certification, it offers a rare combination of intelligence and privacy that doesn't compromise on either.

Worth checking out if…

You use Gmail on a Mac with Apple Silicon, want AI-powered sorting and drafting, and refuse to trade your privacy for convenience. Quartz is free for beta users and available now on Product Hunt.