I think you should give (mostly) everything a fair try. At least anything that's "different" than what you're used to. As a programmer, you should always be striving to improve your workflow. The ideal workflow is different for everyone. The standard text editing experience with a mouse / using control arrow keys etc to navigate is fine and familiar. But you should really at least experiment with modal editing like vim or kakoune. Beyond just the way you type text, the way you interact with the editor (and by extension the project you're working on as a whole) is important to consider too. Make files are a great way to simplify those complex commands you run, but there may be a way to achieve those actions in the editor you're using. Compilation, testing, and running code is just one thing. But what about something like git? Magit on emacs is an example of an extremely well thought out integration of git into an editor. Autocompletion is a whole other story, but you can get that in mostly any kind of editor with LSP integration.
Anyways the point I'm trying to make is that you should never be stagnant in how you program (editor) and what you program (language, paradigm, domain, etc).
Only time you should be stagnant is once you've at least considered the other options and you know what works for you. :)
I guess it defeats the point of self hosting. But a common theme is that email self hosting is extremely difficult. Many things to take into account. I'd say go for it and maybe you'll learn a lot in the process. But if you give up on self hosting it, but still want yiue own mail server on your own domain, then I'd say use infomaniak.