Getting started
What OpenMail is, what it runs on, and how to set it up.
OpenMail is a mail client for macOS. It syncs your accounts into a SQLite database on your Mac and works from that copy. Reading, searching and organizing happen locally. Changes you make offline go into a queue and reach the server when you are back online.
The desktop app, the openmail command line tool and the MCP server all use the same local database.
Status
OpenMail is in early testing. There is no public download yet. To use it, build it from source.
Requirements
- macOS 13 or later, Apple silicon or Intel. Semantic search needs Apple silicon.
- A Gmail account, a personal Microsoft account (outlook.com, hotmail.com, live.com), or a mailbox with IMAP and SMTP access.
First run
- Build OpenMail from source and open it. The add account screen appears.
- Pick Gmail, Outlook or an IMAP provider. See Adding accounts.
- OpenMail downloads recent mail first, then fills in older mail in the background.
- A card above your mail asks how remote images should load. See Security model.
What the app includes
- Sync and organize. Incremental sync, an offline change queue, batch actions, undo history that survives a restart, snooze (new Inbox mail in a snoozed conversation ends the snooze, as in Gmail), labels and nested folders, Gmail categories, server filters and auto-replies.
- Compose. Drafts autosave and sync both ways. Rich text, plain text and Markdown. Reply, forward and forward as attachment, send and archive, undo send from 0 to 30 seconds, attachment reminders, templates, named signatures, send-as addresses and contact completion. When a quoted original has formatting the editor cannot keep, you write your reply above a read-only Quoted text section that is sent unchanged. Edit quoted text makes it editable after a warning.
- Read and search. Conversation and single-message views, find in message, raw source and EML export, print and PDF, remote image control and tracker blocking. Local full-text search supports boolean, phrase, date and size operators and can include server results.
- On-device indexing. Optional OCR for images, text from PDFs and semantic search. Models are downloaded once (about 226 MB) when you turn this on, and processing runs on your Mac. Semantic search needs Apple silicon: ONNX Runtime ships no Intel Mac build, so on an Intel Mac the switch is off and OCR and PDF text still work.
- Mac app. Spaces that group accounts, notification schedules, a menu bar item, multiple windows, spell check, mailto links and three keyboard shortcut sets. The interface is available in English, Simplified Chinese, Czech, Dutch, French, German, Italian, Japanese, Russian and Spanish.
- AI. Off by default. See AI features.
- CLI and MCP. See CLI and MCP.
Where OpenMail keeps data
| Data | Location |
|---|---|
| Mail, attachments, search index, settings | ~/Library/Application Support/openmail |
| Refresh tokens, IMAP passwords, AI API key | macOS Keychain |
| Your own OAuth client ID and secret, if any | config.json in the data folder, mode 600 |
| Attachments you open in other apps | ~/Library/Application Support/OpenMail/Opened Attachments |
| Diagnostics log and its hash key | diagnostics/ and diagnostics.key in the data folder |
Set the OPENMAIL_HOME environment variable to use a different data folder for the app, CLI and MCP server. Opened attachments stay in the app's own folder either way.
When you open an attachment, OpenMail writes a copy and hands it to the other app, so edits you save there stay. Copies you have not changed are deleted 7 days after you last opened them, unless another app still has the copy open (its lock file is in the folder); Settings → Local cache clears it anyway. Copies you edited stay until you clear them in Settings → Local cache. Removing an account deletes its unchanged copies. Time Machine skips the folder. If Open attachments from is set to Downloads, copies go to your attachment folder instead and OpenMail never deletes them.