Ah, interesting! I don't think Thunderbird has this as a feature.

What could be the us-case. Can you share more info on who would send extra long messages?

Thanks again!

There's no option to wrap received messages. If it doesn't wrap, it's due to bad formatting by the sender. But if by 'message pane' you mean the text of a replied or forwarded message, or a new composed message, there are ways to wrap the text.

@sfhowes, thanks,

sorry, as i made a mistake with my original question. please allow me to re-ask.

how to disable word wrap in the message pane? i want thunderbird NOT to wrap long lines.