I am pretty new to Unix shell scripting, but wondered if anyone could help (in layman's terms if possible!!)

I have a shell script which ultimately sends an alert to an email address if part of a batch of programs fails. Here's the script that sends the email:

Script: 6check.csh
#!/bin/csh
set alertperson = `cat /export/home/bdodym/alert.person`
if (-f critabend.tag ) then
cat callout6.msg | rmail $alertperson
rm critabend.tag
endif

This is where $alertperson will be forename.surname@address.com designation in the alert.person script

From the command line, all runs fine.

However, if I run through cron, it still seems to be executing the scripts (e.g files are created that I'm asking the script to do generally), but the email is not being sent as I would hope. In the below crontab, 6start.sh has a number of scripts to run through, the last of which is 6check2.csh (as per above)

crontab -l
#!/bin/csh
#############################################
# Minute Hour Month Day Month Weekday Command
# ___________________________________________________________
# 0 01 * * * Job_1
#
51 * * * * /export/home/bdodym/6start.sh

Does anyone know if there is anything additional I need to do add to either the script, or cron, to ensure the email sends? I think (from my VERY limited knowledge of this kind of thing!) that its something to do with the fact cron is running in the background rather than the terminal, as per the command line success. But, this is the final piece of the jigsaw and I just need to ensure I can get it to fit!!