Line breaks in the message are converted to <br> and escaped in HTML mail

As the title says... when I enter newlines in the textarea for the message and send it as HTML mail, the line breaks get converted to <br> tags and are escaped (probably thanks to twig's autoescaping). As a result, the br tags are visible as plain text in the email instead of acting as line breaks. The setting "Allow HTML in personal messages" is off.

I would expect the module to either A) convert newlines to br tags and allow them in the HTML, or B) leave the newlines as they are so they will simply become spaces in the rendered HTML.