Monit

sudo nano /etc/monit/monitrc

changed:

set alert ractive74@gmail.com

set httpd port 2812 and
    use address localhost  # only accept connection from localhost
    allow localhost        # allow localhost to connect to the server and

  check system $HOST
    if loadavg (1min) > 4 then alert
    if loadavg (5min) > 2 then alert
    if cpu usage > 95% for 10 cycles then alert
    if memory usage > 75% then alert
    if swap usage > 25% then alert

 check network public with interface eth0
   if failed link then alert

sudo systemctl restart monit

sudo monit -t

sudo monit status