-if type -p $FORMAIL >/dev/null ; then
- msgid=$(formail -c -z -x Message-ID | head -n1)
-elif type -p $REFORMAIL >/dev/null ; then
- msgid=$(reformail -c -x Message-ID: | head -n1)
+if is_callable $FORMAIL ; then
+ msgid=$($FORMAIL -c -z -x Message-ID | head -n1)
+elif is_callable $REFORMAIL ; then
+ msgid=$($REFORMAIL -c -x Message-ID: | head -n1)