When I reply to an HTML message, a horizontal scroll bar appears. Horizontal scrolling or widening the window is necessary to read the message that I am responding to. But sometimes I must widen the window to an extreme width, which I don't like to do, or scroll horizontally to read the text, which I don't like to do. I end up having to look at the original message in a separate window in order to write a response to it because I cannot read it easily in the quoted text area of the composition window. Other e-mail programs wrap text better within a window of any width and they do not require horizontal scrolling. The only way I know to deal with this problem in Thunderbird is to use the re-wrap menu option. But even that does not get rid of horizontal scrolling, and I do not like the fixed line length that it imposes. I want text to wrap dynamically in windows, as it does in, well, just about every text handling program that I've used in the last 40 years. Is there a better way to eliminate the need for horizontal scrolling? Something in configuration settings? Something in CSS? In case it matters: I write plain-text messages.