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.

How to insert a text box in Google Docs Within Google Docs there is a pop-up version of Google Draw that allows you to insert shapes, text boxes and drawings into your document. Need a break?

Add a personal touch with an image in your Gmail signature. Or if you're a Workspace admin, put an image in the outbound footer of every email from your organization.

The window also contains two text boxes in the Dimensions section that allow you to set your image's dimensions. When you click "Insert," Tumblr adds the image to the editing box.