I have done a basic setup on ubuntu 8.04 and am having a problem with mail not getting delivered.

It seems to be a DNS problem, because if i look in the queue it tells me that it has tried to connect to itself and has been refused the connection.

The address it is trying to connect to is the external addreess and the origin host/ip is

i assume i just need to tell the server that it is itself so the dns lookup succeeds.

Please can you tell me where to configure this.