I'm trying to do the exact opposite of How To Make Thunderbird Compose Mail With "Body Text" As Default?. So my current default setting for composition is "Body Text", but I want it to be "Paragraph".
Just doing it the opposite way of the accepted answer doesn't work: If I select Format⇒Paragraph⇒Paragraph (from the menu bar), it does the formatting for the current e-mail; when I open another message, however, it starts out with "Paragraph" selected, but as soon as I type the first letter of my e-mail, it changes to "Body Text".
Is this a bug? Can anybody reproduce this behavior?