I dread receiving an e-mail from someone who has an underscore contained in their e-mail address.  Whenever I attempt to send a reply, it fails to send and ends up stuck in my OUTBOX.  This happens whether I retype another e- mail, or reply using the original.   I am using Windows Live Mail, if that makes any difference !    Can anybody out there explain what is going on and ( hopefully) help me overcome this annoying irritant.