Not OP but the best email client in Emacs is RMAIL. So dead simple that you can teach it to your grandpa in a couple hours. I use Gnus because it does nntp thus

Not OP but the best email client in Emacs is RMAIL. So dead simple that you can teach it to your grandpa in a couple hours. I use Gnus because it does nntp thus helping me keep my inbox clean while still being able to follow many mailing lists. Also, many times people don't CC you when responding on lists so if you don't gmane+nntp, many times you don't get the responses without subscribing. I wonder what weird programs these use.