I am searching for transparent proxy for SMTP. I have found some 
solutions that not exactly match my demand (all using relay and 
one to many connections). I need a solution that is able to handle 
many to many connections on the incoming and outgoing side, 
because we do not want to use any (external) relay hosts. All 
traffic should be send to a special box appearing as our normal 
mail-server and then delivered to our internal mail-system. Outgoing 
mail should be send to the same box and then directly forwarded to 
the reciptions mail-server (without using any relay services).

I think an outgoing one to many connection with using a relay 
system is no problem while using delegate. But how delegate 
handles many to many connections? Is it able to handle things like 
this?

Grettings,

Roland Pelzer