It's funny how some Smug Emacs Lisp-guy are confronted with why the Emacs with extension mail client was deprecated. It must have been some life changing experience chatting with non Smug Emacs Lisp-guys people actually wanting to use Emacs.

I can quite understand why you would want Emacs for Customer support emailing, with the ability to semi-automate tasks and extend extensions. If it's your full time job to write quite similar emails, it's probably worth the effort.