Emails marked as "Norton Anti Spam" and "Suspicious Message"

I am receiving emails that Norton is marking as "Norton Anti Spam" in the subject line and this morning, emails from Paypal are marked as "Suspicious Message". I have the paypal email address in my address book, should this not tell Norton that these emails are safe? I can't do anything about the emails marked as "Norton Anti Spam" as they are all from customers to my small business so I am unable to add them to my address book. These emails do not go to my spam folder, just to my inbox, so I am unable to select "this is not spam". I just have to keep remembering to remove the "Norton anti spam" from the subject line when I reply as I don't want it there.

Is there any setting I can change or something I can do to stop this or do I just have to live with it?

Thanks.