Configuring red hat linux crontab

OverSea

Hello everyone,

I'm configuring my server and I want to make something like this.
I want to count the number of processes of a user and than if the number
is less than a threshold value, send an email to my email.

##########################################
#!/usr/bin/bash
processos=`ps -ef|grep portal|wc -l`
$processos= expr $processos
if $processos -lt 100 then
        echo "ortal em baixo" >; /usr/local/bin/test.txt
fi.
##########################################

OK NOW IS MY QUESTION:
How can I send an email from linux to my external email, using my
exchange server????

Regards,
OverSea