alternatives to
Microsoft's mail and calendar app for Windows, macOS, mobile and the web. A closed product from Microsoft.
| Tool | Fit | Stars | Licence | Terms | Self-hosted | Language | Latest | Last push |
|---|---|---|---|---|---|---|---|---|
| Mailspring | Partial | 18k | GPL-3.0 | Open source | No | TypeScript | 1.26.0 | 2026-10-06 |
| Thunderbird for Android | Partial | 14k | Apache-2.0 | Open source | No | Kotlin | K9MAIL_24_0 | 2026-10-06 |
| FairEmail | Partial | 4.7k | GPL-3.0 | Open source | No | Java | 1.2338 | 2026-10-02 |
3 alternatives
:love_letter: A beautiful, fast and fully open source mail client for Mac, Windows and Linux.
Desktop mail for IMAP, Gmail and Office 365 accounts on Windows, macOS and Linux, without a calendar.
Thunderbird for Android – Open Source Email App for Android (fka K-9 Mail)
Mail for any IMAP or POP3 account on Android, with a unified inbox; no calendar.
Fully featured, open source, privacy friendly email app for Android
Privacy-focused mail for any IMAP or POP3 account on Android; no calendar.