Flomsi

Flomsi is an open-source email client designed to make managing mail fast, intuitive and privacy-conscious. Available for macOS, Windows, iOS and Android, it combines a keyboard-first desktop experience with mobile controls tailored to touch. Users can connect Gmail, iCloud, Yandex, Mail.ru, Fastmail and other IMAP accounts, bringing multiple mailboxes into one inbox or allowing them to work account by account.

The client offers search, archive, star, snooze, move, reply and attachment tools, with shortcuts displayed in the interface and a searchable command palette. Customizable Vim and Gmail keymap presets help users keep familiar workflows. On phones, swipe actions, accessible touch targets and an undo window support everyday message handling.

Flomsi’s Rust core stores recent mail locally and applies changes to a local database before syncing them to the server, helping actions remain responsive offline. Mail content is cleaned and displayed without a WebView or JavaScript, and remote images are off by default. The project also provides mailctl, a command-line tool for working with mailboxes.