Which visual editor should be used in the admin panel to create email templates?

Question

Email Marketing

Which editor should be used in the admin panel to create email templates?
Those. essence - on the page there is a heading form "subject of the letter", "content of the letter" which will be sent to the mail to customers.

The functionality is done by itself for a person who is not familiar with html, so you need to use a visual editor in the content of the letter.

Tried Ckeditor5 - but it doesn't fit. adds classes to elements, not inline styles.