HTML comments not visible in Outlook

I’m using comments in some HTML code to make identifying elements easier for future updates. The HTML is being used to create an email in Outlook.

When I comment using

<!— MY COMMENT —>

it is not visible when I view the email source! I can see the HTML code, but the comments I have added are not visible.

The email is composed using a VBO through Blue Prism (not sure if it’s relevant but adding for clarification).

Can anyone shed any light on why this could be happening and how I can make these comments visible.

Thanks!

Comments added to HTML code

Email composed with HTML code

Comments are not visible when viewing source code

Keep in mind Outlook messages are shown and edited using Word, so it converts the original HTML to its internal representation and then back to HTML. See if hidden text would work any better.