FMail3

About

FMail3 is a native macOS app that wraps Fastmail's web interface in a Mac shell, giving you the full Fastmail experience with the window management, notifications, and system integrations you expect from a Mac app. It does not use Electron. Its roots go back to 2019, when it began as FMail, and FMail3 is the latest generation of that ongoing work.

Features include native macOS windows and tabs that are saved and restored automatically, including after restarting your Mac. Version 3.0 adds support for multiple Fastmail accounts, with a single Dock badge counting unread mail across all accounts and per-account notifications. The Dock icon and menu bar show a real-time inbox count via Fastmail's JMAP push connection, and new email notifications let you reply, mark as read, archive, flag, or delete without opening a window. FMail3 can also be set as your default email client, compose in a separate window, and be controlled through Shortcuts, Siri, and Spotlight.

Additional capabilities include exporting emails to PDF, browsing attachments across your mailbox, uploading large attachments to Fastmail Files automatically, creating masked email addresses, and deep link support for Hookmark, Linker, Apple Mail, and Fastmail links. FMail3 also offers an optional integration that lets Claude search, read, flag, mark, and move your mail, without the ability to delete or send messages.