Markdown files in either git or Nextcloud. Mostly VS Codium for editing them but also Kate, Vim, or whatever else is available on the machine I'm using.

Fixedsys

I tried aerc, neomutt, and alpine a while back and preferred aerc. Neomutt was a bit too much config for my liking. Alpine was ok but aerc was my easier to get everything setup the way I wanted.

I manage a number of RHEL/Rocky and Ubuntu machines for work. EL is fine as a server distro but it doesn't make a great desktop distro. The packages are old and I've found it to be missing a number of packages I use on a desktop system. For a desktop, Fedora or Ubuntu is a better fit.