Only sent mail if enabled

data/Dockerfiles/watchdog/watchdog.sh

@@ -124,6 +124,8 @@ function notify_error() {
   else
     SUBJECT="${WATCHDOG_SUBJECT}: ${1}"
   fi
+
+  if [[ ! -z ${WATCHDOG_NOTIFY_EMAIL} ]]; then
     IFS=',' read -r -a MAIL_RCPTS <<< "${WATCHDOG_NOTIFY_EMAIL}"
     for rcpt in "${MAIL_RCPTS[@]}"; do
       RCPT_DOMAIN=
@@ -155,6 +157,7 @@ function notify_error() {
         fi
       fi
     done
+  fi
 }
 
 get_container_ip() {