But another perspective on why use a cli over a regular client. Though there's a bit of a vogue for terminal apps in dev circles, I don't favour them in general. I like GUIs. I want my computer to use 21st century tech for UIs.

But unfortunately (on Linux at least) all the GUI IMAP clients I've tried are terrible. Not because they are GUIs but because they're all either buggy or have awful 1990s corporate interface design or lack even essential keyboard shortcuts, or are just infeasably slow.

So mutt it is, which at least seems to be well-crafted, is quick, and can be configured to be pretty usable. I'd replace it with an excellent GUI app if there were such a thing.