On the Paperform's Agency plan you can customize the HTML of emails. To get started, go to After Submission → Emails, and edit or add the custom email you would like to modify the HTML of.
When you are up to the content area, you can toggle on HTML mode by clicking the code icon to the top right of the content editor.
Any content that had already been entered in the visual editor will now be displayed as editable HTML.
Note: If you change back to the visual editor, any changes you made in HTML mode may be lost.