Sometimes it’s crucial to insert HTML Web programming language into your Gmail messages, such as inserting your signature with an HTML email with common elements such as tables, tags, or links.
To begin with, Gmail DOESN’T allow you to insert your HTML code directly to your content. BUT you can copy the code from another HTML page and copy & paste into the text of a Gmail email to insert the HTML into the message.
Here are the steps to follow.
Select all images you want to include in the Gmail message and upload them to a Web server online or any photo-sharing website. Since Gmail doesn’t allow you to insert HTML directly into the text, you’ll be required to reference images online instead of attaching them.
Create an HTML document using a Notepad, a what-you-see-is-what-you-get editor or an HTML editor. Only reference the location of the images you have online and not the ones saved in your computer when you’re inserting image tags into the HTML code.
View the HTML code in the Web browser. If you made the file on your computer through the Notepad or HTML editor, right-click on the file. Click “open with” and choose from your Web browser from the list. If you’re using the WYSIWYG editor, select the preview option to see the output first.
Highlight all the text on the page that you want to include in your Gmail message and press “CTRL+C” to copy it to your clipboard.
Open your browser and log in to your gmail.com account and click “compose” to craft a new message. Type your email, and then right-click where you want to position the HTML output to appear in your Gmail messages and paste.
Read more about HTML emails at https://www.enginemailer.com/create-html-email.