Netware 6.5 SP8
Groupwise 8 SP1 HP1

This problem isnt dependant on the above versions, I do have it since
long time ago

One Server running MTA and POA
In Console One, Connection Configuration the connection between POA and
MTA is setup using UNC.

When changing this to TCP, using servers IP and Port 7110 (what is
configured for the POA) the MTA always says the PO is closed.