header question

Hello all,

Not specifically Balsa related, but an email correspondent just asked  
my why my email didn't have a Reply-To: header.  I always thought it  
was present, but I see not.  Should it be, or should I just tell him it  
is HIS software that is wrong, since it should reply to the From:  
address if there isn't a Reply-To: ?
(his complaint is that he always needs to type my address in the To:  
field.)

Thanks.

Jack