#!/bin/sh
#
# no-local-recipients – prevent messages to local recipients from being sent
#
# messages with recipients like foo@$HOSTNAME are an indication that mutt has
# not expanded the aliases and thus appended $hostname (cf. $use_domain). In
# my use-case, that's a reason not to send a message.
#
# Copyright © 2010 martin f. krafft <madduck@madduck.net>
# Released under the terms of the Artistic Licence 2.0
#
set -eu

shift # $1 is the tmpfile, we don't need that

HOSTNAME=$(hostname --fqdn)

ret=0
for r in $@; do
  case "$r" in
    (*@${HOSTNAME}*)
      echo >&2 "E: $r seems to be a local recipient, hence I won't send."
      ret=1
      ;;
  esac
done

exit $ret