The Quest GroupWise Migrator for Exchange User Guide makes reference to creating Sub-Domains (Step 3: Create a Temporary Subdomain for the Migration) to allow SMTP e-mail routing for the duration of a co-existence migration but lacks details on how to achieve the setup or how the routing flow will look (when working) between GroupWise and Microsoft Exchange 2007.
The linked document below will attempt to give high-level detail on what a current GroupWise SMTP e-mail routing should currently look like. It will then go on to show what it takes to introduce the Microsoft Exchange 2007 environment. Once the Microsoft Exchange 2007 environment is introduced, this documentation will go over creating DNS MX records and Microsoft Exchange 2007 Smart Host entries so that Exchange 2007 can e-mail GroupWise server and GroupWise Server can e-mail Exchange Server 2007 internally so that a co-existence migration (e-mail route-ability) can take place. It will also go over a typical flow of steps such that each activity can be implemented in order. This document also includes testing activities to be sure the actions are performed correctly to ensure routing is indeed working.
Note: This document does not discuss the Microsoft Exchange Connector for Novell GroupWise. It shows only how to perform SMTP e-mail routing between the GroupWise and Exchange 2007 Servers for e-mail co-existence only (with no Free/Busy).
Please see the attached PDF document titled "GroupWise Server to Exchange 2007 Server SMTP Routing with Sub-Domains - Supplemental" for more information on this topic:
Note: The linked document encompasses a very simple one GroupWise Server, one Exchange 2007 server scenario. Where environments are more complex, the end-user may need to perform additional due-diligence to ensure that SMTP routing between the GroupWise and Exchange 2007 and Internet environments is sound.
Note: Free/Busy is not possible with only SMTP e-mail routing between GroupWise Server and Exchange 2007 server (please see the Quest GroupWise Migrator for Exchange User Guide for more details). If Free/Busy is a business requirement (as it is not a Quest product requirement), then please review the Microsoft documentation for the 'Microsoft Exchange Connector for Novell GroupWise' found at the following link titled "How to Migrate from a Novell GroupWise Messaging Infrastructure to Microsoft Exchange 2003":
Also review the following Quest Solution SOL27618 titled "How can I migrate from GroupWise to Microsoft Exchange 2007 using the Microsoft Exchange Connector for Novell GroupWise?" found at the following link for further details: