Mailspring

About

Mailspring is a native desktop email client for Mac, Windows, and Linux, offering multi-account support across providers such as Gmail, iCloud, Office 365, Outlook.com, Yahoo!, and IMAP/SMTP. Its features include a unified inbox, Gmail-style advanced search across all connected accounts, undo send, a signature editor, grammar and spell checking, translation of messages into several languages, and dark mode with custom themes. The app is free for core use, with deep platform integration such as taskbar badges and notifications on Windows, native notifications on macOS, and system tray support on Linux.

Mailspring Pro, priced at $8/month, adds read receipts, link tracking, send later, follow-up reminders, quick reply templates, and contact and company profiles. Pro also includes Mailbox Insights, which summarizes email activity such as open and click rates. Pro features can be test-driven a few times each week for free.

Mailspring is built and maintained by Foundry376, a small independent team with no outside investors. Its codebase is open-source under the MIT license, and it syncs directly via IMAP, CalDAV, and CardDAV rather than routing email through its own servers. The website states it has over 800,000 downloads since launch.