I have setup the GW/Exchange Gateway and am able to send email beween the 2
systems and do busy searches etc. The problem I am running into is that I
can not get the any email from the outside to go to Exchange. When sending
the email I get back a 550 error message "User Unknown". The user is in the
GW addressbook.

Primary Domain - Runs primary MTA to handle transfers to the POs

Secondayr domain - that has an MTA and hold the GWIA gateway.

Secondary domain - also has an MTA and the Exchange gateway.

All the above mentioned domains run on seperate servers.

The above happens even if you try to reply to a message send from someone
on Exchange.

Any suggestions?