I think you’re mistaken. Mutt works fine with IMAP servers. It’s quite flexible. In the small minority of cases when I need to see the email in a full-blown web browser, it takes two keystrokes to open it there.
Email today should be a no-brainer really. Its a hobby to configure mutt.
If you want your email locally: Use offlineimap to grab the email for example. There are many ways to connect. If not: there are a lot of python/bash scripts to make imap/whatever work with mutt
Almost all of them use configuration files that can be stored in git/svn/csv/etc
I am now looking at what other solution to use. I used to use muttator which was a plugin for thunderbird that emulated mutt behavior and was great, but that hasn't been maintained for >7 years