[AccessD] Thunderbird line wrap

When I reply to emails, in at least some cases the email below my signature (from the person I am 
responding to) does not line wrap, i.e. it just runs off the right hand side of the screen.  This 
makes it difficult to read.  Does anyone know how to cause the line to wrap?

-- 
John W. Colby
www.ColbyConsulting.com