This script removes any clutter of the quoted text when responding. To be used with mutt by adding
set editor = "mutt-trim %s; $EDITOR %s"
to your ~/.muttrc
file.
To fold quotation levels in Vim, add the lines
setlocal foldexpr=strlen(substitute(matchstr(getline(v:lnum),'\\v^\\s*%(\\>\\s*)+'),'\\s','','g'))
setlocal foldmethod=expr foldlevel=1 foldminlines=2
to a file ~/.vim/after/ftplugin/mail.vim
.