Comment 1 for bug 120281

Yes, It seems that when:

user_pref("mailnews.send_plaintext_flowed", true);

the plain text editor supports some sort of internal formatting which when saved
as draft, do Rewrap, copy and paste a quoted text (with ">" in front) is loosed
or it isn't rebuilded in some manner. This way causing the insert of a blank
character before ">" (one of the things which is most annoying) this way
breaking up the format of the quoted text.