The following script sends an alert whenever the exim mail queue is greater than a certain threshold

#!/bin/bash

if [ `/usr/sbin/exim -bpc` -ge 300 ]; then

mail -s "Alert: There are over 300 Emails in the queue!" email@example.com <<EOF

Server Hostname :
`/bin/hostname -f`

Mail IP's (If Any):
`cat /etc/mailips`

Current Mail Queue :
`/usr/sbin/exim -bpc`

Server IP :
`/sbin/ifconfig | /bin/awk '/inet addr/{print substr($2,6)}'`

Thanks,
Support Team.

EOF
fi

Note:
1. Set the desired threshold value for the mail queue
2. Change the alert email from email@example.com to your email ID.
3. If you want the allert to be sent to multiple email addresses you can do so by separating the email ID’s with a comma “,”