Rita,
As Klaus said, the body of the message ends up being the STDIN for your script. The remainder is passed as arguments, for example:
-s [Condor] Condor Job 15.0 condor@cycleserver40vm
I used the simple Bash script below to capture STDIN and arguments:
###
#!/bin/bash
outfile="/tmp/condormail.`date +%Y%m%d-%H%M%S`"
echo "Arguments:" >> $outfile
echo $@ >> $outfile
echo "Stdin:" >> $outfile
while read line <&0; do
echo $line >> $outfile
done
###