When you  peer the list, you  split the list of  recipients among several
machines, and  each machine delivers  to its own sublist.  New recipients
are  assigned to  the  nearest server.  This works  for  both BITNET  and
Internet subscribers, although  of course topological data  for BITNET is
more accurate.  As for  the backbone,  you can always  join it.  The most
important  issue is  what version(s)  you and  the prospective  peers are
running and  are going  to be  running in  the near  future. There  are a
number of problems  with 1.7f peers if Internet-style  addresses are used
for the  list address  (ie "List-Address=  FQDN"), and  this will  be the
default option with 1.8b.
 
If you're running out  of gas on VM the solution  L-Soft recommends is to
move the  deliveries to  a cheap unix  system (a PC  with 64M  can easily
handle 2-3 times  your current workload). This process  is transparent to
the subscribers who just see an extra "Received:" hop.
 
  Eric