I send mail to Unix machines with UPPER CASE addresses and it gets there
just fine.  If I can do it, so can LISTSERV.  I didn't do anything special
so why should LISTSERV.
 
The NETWORK we are on, BITNET/EARN/NETNORTH, is defined to use all UPPER
CASE addresses for both the NJE and MAIL levels.  Anything connected to
such a network that needs all lower case must do such translation in the
connection itself.  Whether this is done in a Unix machine or some other
is not important.
 
My VM userid is listed in a distribution list on a Unix system in lower
case, but it gets here OK because clearly a translation is done.
 
The only problem this network cannot address is one where the case itself
is the distiguishing factor between two users.  If  "<PHIL>" and "<Phil>"
and "<phil>" were 3 different userids, we would be in trouble.  But in
fact they all address me from this node becuase most programs do a translation
between terminal input (lower case) and operating system interface (UPPER
CASE).  You just need only carry this concept over to the interface between
the Unix (lower case) and non-Unix (UPPER CASE) systems.
 
I see no reason for LISTSERV to complicate itself with lower case addresses.
It would result in new problems with regards to sorting and such.  Let's leave
LISTSERV alone and try solving the real problems: why your Unix interface
does not translate data from an UPPER CASE environment to a lower case one.