I&#x27;ve been using Apple Mail since the OS X Public Beta in 2000.  Its address completion and rich text support are entwined in how I think about authoring emails, so I&#x27;m simply more comfortable using it for that purpose. It also helps that Emacs-style movement keys work throughout OS X, including Apple Mail&#x27;s &quot;new message&quot; windows.<p>I did give mu4e a go, i.e. for writing emails, and I never got to a point where it really appealed to me. I do love it, though, for reading and managing my tens of thousands of email messages. It&#x27;s also nice that I can easily create links to messages in mu4e, which I can include in my org-mode files.