+dhcp_mx_add() {
+ local cfg="$1"
+ local domain relay pref
+
+ config_get domain "$cfg" domain
+ [ -n "$domain" ] || return 0
+
+ config_get relay "$cfg" relay
+ [ -n "$relay" ] || return 0
+
+ config_get pref "$cfg" pref 0
+
+ local service="$domain,$relay,$pref"
+
+ append args "--mx-host=$service"
+}
+