>> "Lars" == Lars Magne Ingebrigtsen <larsi@gnus.org> writes: 
 
   > Lars Magne Ingebrigtsen <larsi@gnus.org> writes: 
   >> This is a single paragraph with a long line of text that 
   >> should be long enough here. 
 
   > Yup.  Content-Type: text/plain; format=flowed 

I think one problem is when text is pasted into a message with hardlines
on. Then unwanted newline can be created. Unfortunately as far as I
know, there is now end of line indicator, or hardline indicator, which
would warn you.

See also:  
http://www.emacswiki.org/emacs/GnusFormatFlowed