This is really not a perl problem but a cron issue. If you man crontab you may see:

After cron runs commands according to the contents of your crontab 
file, it mails you the output from standard output and standard 
error for these commands, unless you redirect standard output
or standard error.
[download]

so you need to ensure you do not print any messages to either STDERR or STDOUT. A lot of devs will take a different tact than the one you have. You could set up your script to only print the msg and not e-mail you (and not do anything but exit if nothing new). Then let the cron subsytem mail you the results.

-derby