Mailscript with netcat

#!/bin/bash
test "$#" -eq 5 || { echo "$0 SERVER PORT FROM TO SUBJECT" ;  exit ; }
SAVE=$IFS
FROM=$3
TO=$4
SERVER=$1
PORT=$2
SUBJECT=$5
IFS=" "
DATA=$(cat)
function mail()
{
cat<<HERE
ehlo $(hostname -f)
MAIL FROM: <$FROM>
RCPT TO: <$TO>
DATA
From: <$FROM>
To: <$TO>
Subject: $SUBJECT

$DATA
.
quit
HERE
}
mail | nc $SERVER $PORT
IFS=$SAVE