Hmm, here is a simple cron you could use:

Code:
*/10 * * * * mail -s "Email Is Working" you@yourdomain.com
This will email you@yourdomain.com a blank email every 10 minute with the subject line "Email Is Working"

If you want to do it every day at 1 AM then you could use:

Code:
0 1 * * *  mail -s "Email Is Working" you@yourdomain.com