#!/bin/bash

FILE_NAME=/tmp/my.log

NUM_OF_LINES=$(wc -l < ${FILE_NAME})

if [ "${NUM_OF_LINES}" -ge "20" ]
then
    echo "Triggering Email"
    mail -s "Log" abcd@xyz.com < "${FILE_NAME}"
else
    echo "Log file contains ${NUM_OF_LINES} lines"
fi