Ubuntu :: 9.10 - How To Know If Cron Running Program

I seem to be having a problem with cron. I have a python program that checks a specific directory for pending email scripts written in python.

Code:
#!/usr/bin/python
import os
emaildir = os.environ['HOME']+"/email/"
filelist = os.listdir(emaildir)
for pyfile in filelist:
if pyfile.find(".py") > -1:
execfile(emaildir+pyfile)

This code has been tested and works fine. The problem is that I need cron to run this code every 5 minutes but i can't tell if it is running: Here is my cron code:
5 * * * * /home/username/custom/CheckEmail.py >>/home/username/custom/email.log 2>&1

I activated the log (I think) but all i get is /var/log/cron.log and that only logs when I activate/deactivate or edit the cron file. is there anything else i need to set for this to work? I am running Ubuntu 9.10.