email ?security?

I am not really sure how to categorize this, but I will give it a shot. A user showed me an email he received yesterday. This user is using Office2000 on a Win98 box.

The email received with text and included the original thread. When he clicks "forward" to forward the email (or "reply") the text sent to him disappears and he can only see the original thread.
Has anybody heard of such email security where you can cause text to only be viewed and not be altered and disappear upon forward/reply?

Let me add, he can copy and paste the text. He also told me the person who sent it to him is a real SOB and would do such a thing if it existed.

Thanks.