Email alert script

I need to code a script, which will run via cron, every 30 minutes.
The script will read a file containing a date&time and number (which represents disk space). The file gets appended to every 30 minutes. Here's a sample of the file:

CPU 1:04/25/02 1:00 am:1972554
CPU 1:04/25/02 1:30 am:1960223
CPU 1:04/25/02 2:00 pm:1953990

If that value falls below 1000000, I wish to send a email alert to about 3 users that says something like:

"04/25/02 2:00 pm: Check disk space on CPU 1"
Thanks

See:

tail -n 1

cut -d: -f number

and test command.

Regards. Hugo.