FMail3 for Mac

Email provider Fastmail offers native iOS and Android clients but lacks a dedicated macOS application. While Fastmail’s web interface is excellent, it has one significant limitation: it cannot behave like a native mail application on macOS.

The Problem

The primary issue is that the web interface cannot handle email links (mailto: links) properly. When you click on an email link, macOS defaults to opening the built-in Mail application instead of Fastmail’s web interface—which defeats the purpose if you’re trying to use Fastmail as your primary email client.

The Solution: FMail3

FMail3 represents a modern evolution of FMail2, built in accordance with Apple’s design guidelines. This wrapper application allows Fastmail’s web interface to function more like a native macOS mail client.