In order to embed HTML, you actually need to copy the rendered HTML from either an existing web page or WYSIWYG HTML editor and then paste it into Gmail.

You can embed a Google Map into a personal website using a HTML code from the map's Menu tab. Here's how to do it.

How to Embed HTML Links and Badges. Hyperlinks make it possible for Web surfers to move from one website to another with simple mouse clicks. These links are coded in HTML using the "" tag.