mcomp: check message before sending

mcomp

@@ -109,6 +109,7 @@ while :; do
 				c=
 			fi
 		else
+			if mmime -c <$draft; then
 				if sendmail -t <$draft; then
 					if [ "$outbox" ]; then
 						mflag -d $draft
@@ -120,6 +121,10 @@ while :; do
 					echo "mcomp: sendmail failed, kept draft $draft"
 					exit 2
 				fi
+			else
+				echo "mcomp: message needs to be MIME-encoded first."
+				c=
+			fi
 		fi
 		;;
 	c|cancel)