User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.7) Gecko/20040707 Firefox/0.9.2 Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.7) Gecko/20040707 Firefox/0.9.2 It seems mozilla mail and thunderbird fail to display a line wrapping in Windows. However, when view the "message source" the line indeed wrapped. For example, in thunderbird, "View-->Message Source" display the wrapping well. And the same mail displays the wrapping well in Outlook/Outlook Express. (I indeed want to abandon Outlook) I suspect the Mail client fails to differentiate the CR/LF between Unix and Dos formats. Reproducible: Always Steps to Reproduce: 1.Compose a new message, input a long line to have the mail client to wrap it 2.send it to your self 3.Check the result in ThunderBird: it failed to wrap, say at 72 char. Actual Results: The TBird/Mozilla Mail failed to display the line wrapping, even indeed there is a wrapping in the mail message source. Expected Results: Display the wrapping right in Windows/Dos format. I first found this problem in ThunderBird 0.7.1. Later, I test a fresh installation of Mozilla (include mail), which has the same problem. T tested the latest download within 2 weeks, the problem reproduces every time.

Help_>About:config Check your setting for "mailnews.display.disable_format_flowed_support" Try setting this to true. <http://oceanpark.com/notes/howto_mozilla-mail-plain-text-word-wrap.html>

This "problem" is in fact deliberate; it is how format-flowed text is intended to work. You may choose to disable it, as noted in comment 1; but before you do that, I recommend reading bug 168420 and the FAQ attached to that bug. *** This bug has been marked as a duplicate of 197130 ***