emailing myself when a ping command fails via crontab????

Hi, I have a command set up in crontab as goes: 0,20,40 9-16 * * 1-5 ping -c2 111.111.111.111 >> file.log basically this pings one of our external network servers every 20 mins between 9am and 4pm.... it then outputs the ping to a text file for me to observe and ensure connectivity is in place, however I tend to forget about this and now want to set a command up to email me via sendmail when the ping command fails.... Is this possible? and can anybody show me how? Thanx Damian Buckley