The MTA handles message transfer between post offices.
The message flow diagrams in GroupWise 7 Troubleshooting
3: Message Flow and Directory Structure focus on TCP/IP
links because they are the most common and convenient (unless you
have a post office and a domain on the same server). For diagrams
that include mapped/UNC links, see GroupWise
6.5 Troubleshooting 3: Message Flow and Directory Structure.
For an explanation of link types and link protocols, see Understanding
Link Configuration
in Domains
in
the GroupWise
7 Administration Guide.