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.

I have tried Google, and I have even tried asking an Outlook MVP. I now turn to the hive-mind. Is there any way to insert HTML into an email similar to the ...

The block inserts at the cursor position. You can also right-click the applicable text block and select an insert location from the list. in both cases, the text block drops into the email ...