Our current msmtp package (1.4.24-1) does not install scripts/vim/msmtp.vim which provides syntax highlighting for the ~/.msmtprc file.

Below please find a PKGBUILD that does this.

Thanks,
Pat

=== PKGBUILD ===
# $Id: PKGBUILD 122860 2011-05-06 19:46:40Z eric $
# Maintainer: tobias <tobias@archlinux.org>
# Contributor: Ben Mazer <blm@groknil.org>

pkgname=msmtp
pkgver=1.4.24
pkgrel=2
pkgdesc="A mini smtp client"
arch=('i686' 'x86_64')
license=('GPL3')
url="http://msmtp.sourceforge.net"
depends=('gnutls' 'libidn')
provides=('smtp-forwarder')
install=${pkgname}.install
source=(http://download.sourceforge.net/sourceforge/msmtp/${pkgname}-${pkgver}.tar.bz2)
md5sums=('3ed704fbd3e7419cab5c65bb7928d9ba')

build() {
cd "${srcdir}/${pkgname}-${pkgver}"
./configure --prefix=/usr --sysconfdir=/etc --with-ssl=gnutls
make
}

package() {
cd "${srcdir}/${pkgname}-${pkgver}"
make DESTDIR="${pkgdir}" install

# this can not be the default
#install -Dm644 doc/msmtprc-system.example "${pkgdir}"/etc/msmtprc

# add vim syntax file
install -Dm644 scripts/vim/msmtp.vim "${pkgdir}"/usr/share/vim/vimfiles/syntax/msmtp.vim
}