Email alert is one of the important to know number of  Email's in  queue, the following script send an email alert more than 100 email in queue,


#Email queue Notification ,
#!/bin/sh
#Email Queue:

MQUEUE=`find /var/spool/exim/input -name '*-H'|wc -l| sed -e "s/ //g"`
EMAIL_ID="your_email@gmail.com"

if [ $MAIL_QUEUE -gt 100 ]; then
echo "EMAIL QUEUE SENDING MORE THAN 100= $MAILQUEUE" | mail -s "Email queue Alert:"$EMAIL_ID
else
exit
fi


Another way is,


#Email queue Notification
#!/bin/sh
MAIL_QUEUE=`exim -bpc`
EMAIL_ID="your_email@gmail.com"
if [ $MAIL_QUEUE -gt 100 ]; then
echo "EMAIL QUEUE SENDING MORE THAN 100= $MAIL_QUEUE" | mail -s "Email queue Alert:"$EMAIL_ID
else
exit
fi