Norton Email Error Message

I have a neat little program that lets me check my email, preview it and even bounce the email as if my email address does not exist before I download my email to my email program, but since I built my new computer, every time I bounce an email, I get the message seen in the following screen shot.  What does this message mean?  Is Norton preventing me from bouncing the email?  If so, how can I fix that?

norton_email_bounce_message.jpg