HTML Report from mail in ksh 88

Hi Team,
I'm trying to send HTML Report from email using the below script (Using ksh 88 version)

#!/bin/ksh
set -x
SUB="Test Email"
Mail_Body="This is for testing"
Send_Mail_HTML()
{
        (
         echo "FROM: abcd@test.com"
         echo "To: abcd@test.com"
         echo "Subject: $SUB"
         echo "MIME-Version: 1.0"
         echo "Content-Type: text/html"
         echo "Content-Disposition: inline"
         cat "$Mail_Body"
        ) | /usr/sbin/sendmail -t
}
##################Main Script Block############
Send_Mail_HTML

I'm getting the below error

$ ksh test_mail.sh
+ SUB=Test Email
+ Mail_Body=This is for testing
+ Send_Mail_HTML
cat: cannot open This is for testing

Please help me out with this ..

Presumably because the file This is for testing does not exist.

Either create it, or (if you just want the contents of the variable Mail_body) change the cat to an echo .

Might it have anything to do with the fact that your trying to use spaces in your filename?