Exo

Free plan Mac

What Exo is

Exo is a free, open-source, AI-native desktop email client for macOS that connects to Gmail and Google Calendar. Claude assigns incoming mail high, medium, low, or skip priority, while AI drafts use thread context, sender background, and the user’s writing style. The Cmd+J agent can draft replies, look up information, forward messages with context, and work with custom agents. Sender lookup can show role, company, and LinkedIn details in a sidebar. Inbox tools include priority and custom tabs, natural-language snoozing, archive-ready detection, and hybrid local plus Gmail search. Composition supports rich text, multiple signatures, scheduled send, undo send, inline images, and attachments. Exo works offline with queued actions and incremental background sync. Email data and OAuth tokens stay on the computer; AI runs locally or through a provider configured with the user’s API key. Runtime extensions, custom agent providers, sidebar panels, and MCP server tools are supported. The Free plan costs nothing and requires macOS, a Gmail account, and an Anthropic API key.

Who it suits

Exo suits keyboard-driven users who live in their inbox and want AI-assisted triage, drafting, search, and calendar access on macOS. It also suits users who prefer local storage and offline operation.

What it does well

Free macOS plan
AI priority and drafting
Gmail and Google Calendar connection
Offline queued actions
Local email and token storage

What to know first

macOS only
Requires a Gmail account
Requires an Anthropic API key
AI may send content to configured providers

Plans

Plan	Billed and limits	Price
Free	macOS · Gmail account · Anthropic API key	Free

As exo.email lists them, read 11 Oct 2026. The maker's own page has the final word.

Verdict

Exo combines AI inbox organization, drafting, calendar access, offline work, and extensibility in a macOS client. Its local storage approach is clear, but using provider-based AI can send email content through the provider selected with your API key.

Facts from Exo's own pages

Agent: The Cmd+J agent can draft replies, look things up, forward with context, and work with custom agents. · exo.email, 11 Oct 2026
AI data flow: AI features process email locally or through an AI provider the user configures; email content may be sent to that provider using the user's own API key. · exo.email, 11 Oct 2026
App coverage: desktop · exo.email, 23 Sept 2026
Calendar tools: Yes · exo.email, 23 Sept 2026
Composition: The client supports rich-text composition, multiple signatures, scheduled send, undo send, inline images, and attachments. · exo.email, 11 Oct 2026
Drafts: AI-generated drafts use thread context, sender background, and the user's writing style. · exo.email, 11 Oct 2026
Email and calendar: Exo connects to Gmail and Google Calendar, with multi-account email switching and a calendar sidebar. · exo.email, 11 Oct 2026
Extensions: Exo supports runtime-installable extensions, custom agent providers, email-scoped sidebar panels, and MCP server tools. · exo.email, 11 Oct 2026
Free plan: Yes · exo.email, 23 Sept 2026
Local storage: Email data and OAuth tokens are stored locally on the user's computer, and Exo says it does not operate servers that store email data. · exo.email, 11 Oct 2026
Offline access: Yes · exo.email, 23 Sept 2026
Offline use: Exo supports offline use with queued actions and incremental background sync. · exo.email, 11 Oct 2026
Organization: Features include priority and custom inbox tabs, natural-language snoozing, archive-ready detection, and hybrid local plus Gmail search. · exo.email, 11 Oct 2026
Product: Exo is an open-source, AI-native desktop email client that gathers context for emails and can draft replies in the user's style. · exo.email, 11 Oct 2026
Security: Exo says OAuth tokens and local data use the operating system's standard security mechanisms, and its source code is publicly reviewable. · exo.email, 11 Oct 2026
Sender lookup: Automatic web search surfaces sender context such as role, company, and LinkedIn in a sidebar. · exo.email, 11 Oct 2026
Scheduled sending: Yes · exo.email, 23 Sept 2026
Support: The privacy policy directs questions to an issue on GitHub. · exo.email, 11 Oct 2026
Triage: Claude analyzes incoming email and assigns high, medium, low, or skip priority. · exo.email, 11 Oct 2026
Who it's for: The site describes keyboard-driven navigation and says the client is built for people who live in their inbox. · exo.email, 11 Oct 2026

Where Exo stands on Freedom251

Email clients#61 of 142