The issue then, is that the email messages are getting tagged as SPAM when it reaches them.
From your perspective the only thing you can do is to advise them to add your email address as a "friend" and also consider the style and content of the email that you are sending out. All anti-spam products, McAfee included, use heuristics to try and determine if an email is spam. Something about your email is making the various filters think you're sending junkmail.
But my prospective will added me only on his own email client. But not in the McAfee black-list.
I guess it's easy to lock anyone email just by sending to McAfee a request that that guy a spammer. And he will be added to the black list.
How you will distincted if the people that requested to add me to spam-list is not a spammers?
Why you trust them and not trust me?
I checked sending the email to the same receipient from the two email accounts from one doman. The same subject, the same content but second one was marked as spam. It's very pity.