How can I send an alarm email

this is mysql config：

• title:monitorThreads position: [[0, 32], [80, 12]] rate-ms: 1000 sample: $mysql_connection -e "show status like 'Threads_created';" | awk '{print $2}' border: false
  color: 178
  triggers:
  • title: Threads_created condition: echo "$cur < 17" | bc -l actions: terminal-bell: true
    visual: true script: | echo "alert：Threads_created is ${cur}" | mail -s "alert mysql" [email protected]

But I didn't receive the email，why？？？？This script is not working，how to do？