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Metis Suite vs Mailspring
Mailspring is a native desktop email client for macOS, Windows and Linux, open source under GPL-3.0, with Mailspring Pro at $8 a month and a local MCP server since version 1.23. Metis Suite runs on a server and works in any browser, so phones and teammates reach the same accounts, and it adds a built-in AI agent with approvals, workflows, and drives from Google, Microsoft and your own servers.
Mailspring facts checked on October 21, 2026
| Feature | Metis Suite | Mailspring |
|---|---|---|
| License | Open source, AGPL-3.0-or-later Source | GPL-3.0 per the repository (the homepage says MIT) Source |
| Self-hosting | Yes, with Docker Compose on your own Linux server, or run for you on Metis Cloud Source | No server; a desktop app that syncs directly with your provider Source |
| Mail accounts | Gmail, Microsoft 365 and Outlook.com, Zoho Mail, and IMAP servers the instance owner adds Source | Gmail, iCloud, Office 365, Fastmail, Outlook.com, Yahoo and any IMAP/SMTP server Source |
| Calendar | Google Calendar, Outlook, Zoho Calendar and CalDAV in one view, with editing and RSVPs Source | CalDAV calendar with day, week and month views in recent releases Source |
| Files and drives | Google Drive, OneDrive, S3, WebDAV, FTP and SFTP in one explorer, with previews Source | No drive browser; attachments with preview Source |
| AI assistant | One agent across mail, calendars and drives; sending, deleting and every calendar, drive or workflow change waits for your approval Source | None built in; local agents connect over MCP Source |
| AI model | Bring your own: OpenAI, Anthropic or any OpenAI-compatible endpoint, including one you run yourself Source | No bundled model; you bring your own MCP client Source |
| MCP | Built-in MCP server with OAuth for Claude, Cursor, Codex and VS Code; sending and deleting stay off until you enable them Source | Local MCP server, off by default, with one access level from read-only to read-write-send Source |
| Automation | Visual workflows on new mail, a schedule, a manual run or before a send, with AI Ask and Branch steps Source | Client-side mail rules, snooze, reminders and send later Source |
| Apps | Web; desktop apps for macOS, Windows and Linux; an Android app; no iPhone app Source | macOS, Windows and Linux; no web or mobile app Source |
| Price | Free to self-host; Metis Cloud from $10 a month billed yearly, or $12 monthly, per instance | Free with weekly limits on Pro features; Pro $8 a month Source |
Choose Mailspring if
You want a native desktop app that syncs directly with your provider, with no server to run.
Choose Metis Suite if
You want a web suite for every device, shared mailboxes for a team, a built-in agent, or file drives next to mail.
Mailspring is made by Foundry 376. Every fact about it on this page comes from its own website, documentation or source code, as linked, and was checked on October 21, 2026. Products change: if something here is out of date, write to contact@astraqcyberdefence.com and we will correct it. All trademarks belong to their owners.