[grail]

Currently, I have a Contact Us form integrated on my webpage, I am looking to add another box which displays what the message will look like after the "Send" button has been pressed.

Can anyone assist me?

[.kr.]

What's you issue?
Show me the Php-Source

[Rushax]

We need you to elaborate a bit more on what you're using for the site, is it on a CMS such as WordPress? If so a plugin called Contact Form 7 already handles this for you.
If it's a static site, you may want to look at Bootstraps alert classes that are already preset (if you're using Bootstrap)
https://getbootstrap.com/docs/4.0/components/alerts/

If not, you could just inspect the CSS code from that, initially hide the alert message, use some simple AJAX on-submit and if success, add a class to the alert message.
You may want to add two though, one for success and the other for failed/error.

[saint psycho]

so what you're looking for, is kind of a live preview, of what the email will look like, when it has been sent?