diff --git a/target/start-mailserver.sh b/target/start-mailserver.sh
index a7862537..c7fc4b7b 100644
--- a/target/start-mailserver.sh
+++ b/target/start-mailserver.sh
@@ -15,6 +15,7 @@ DEFAULT_VARS["ENABLE_MANAGESIEVE"]="${ENABLE_MANAGESIEVE:="0"}"
 DEFAULT_VARS["ENABLE_FETCHMAIL"]="${ENABLE_FETCHMAIL:="0"}"
 DEFAULT_VARS["ENABLE_LDAP"]="${ENABLE_LDAP:="0"}"
 DEFAULT_VARS["ENABLE_SASLAUTHD"]="${ENABLE_SASLAUTHD:="0"}"
+DEFAULT_VARS["SMTP_ONLY"]="${SMTP_ONLY:="0"}"
 DEFAULT_VARS["VIRUSMAILS_DELETE_DELAY"]="${VIRUSMAILS_DELETE_DELAY:="7"}"
 DEFAULT_VARS["DMS_DEBUG"]="${DMS_DEBUG:="0"}"
 ##########################################################################