Shell Programming and Scripting

Hi all,

I wrote a shell script to send a mail, it is not showing any errors but i didn't receive any mail

#!/bin/ksh

. ./set_mail_details.ksh

echo 'In script'
subject=$1
echo '\nsubject'
echo $1
echo "$subject" | sed 's/~/ /g' | read sub
body_of_email=$2
echo '\nBody'
echo $2
echo '\nMail List'
to_list=$3
echo $3
echo "$body_of_email" | sed 's/~/ /g' | read body
(echo "$body";echo '\n';cat U.CUE_CPM )| mailx -s "$sub" -r some_address@some_mail.com "$to_list"
if [ $? -eq 0 ]
then
echo "Mail is Sent"
else
echo "Mail is not sent(In script)"
fi

output:
$ send_mail.ksh hi test some_address@some_mail.com
In script
subject
hi
Body
test
Mail List
some_address@some_mail.com
Mail is Sent

can any one please help me what is wrong in my script.