Challenges of Migration from GroupWise to Exchange 2010: Co-Existence

This article will discuss a high level overview about the migration from GroupWise to Exchange 2010.


The following steps summarize the migration process from GroupWise to Exchange 2010:

1. Design Exchange 2010.

2. Implement and configure Exchange 2010.

3. Select the migration software (3rd party).

4. Setup Co-Existence between GroupWise and Exchange.

5. Migrate the users’ mailboxes.


In this article I will concentrate on Step 4. In my environment I will use Quest tools for the migration. Reading most of Quest guidance they covered the implementation of the tool and step 5 only, while the most important step (Step 4) is not covered.

Simply co-existence including mail flow is product configuration and not relevant to the migration software. In this article I will explain how to have mail flow between both systems and also will cover share SMTP namespace.


There are three options to for mail co-existence:

1. Single Namespace: in this scenario we will have one domain to cover both systems. As example domain will be used in both systems, each system will forward the emails to the other if there is no recipient locally as follows:

When users in GroupWise send email to one of Exchange users, GroupWise will not find a mailbox for the recipient locally and will forward the email to Exchange, same from Exchange side.

Problem: while this is easy to configure from Exchange side, I couldn’t find a way to do it from GroupWise side that will not result in loop. To avoid loops we must have one side responsible on sending NDR if it can’t find the user.

2. Different Domains: in this scenario we will have two different domains, one for each system:

a. for GroupWise users. Exchange users  will send to users in GroupWise using this address.

b. users in GroupWise will send emails to Exchange users using this address.

3. Hybrid: to mix both approaches as follow:

a. Exchange Side: will use single namespace, Exchange will have mail contacts for all users in GroupWise, when mailbox in Exchange is sending to one of the GroupWise users (contacts in Exchange), Exchange will forward the email to GroupWise server. This will maintain GroupWise as the owner of the domain, which means if the user is not exist in GroupWise, GroupWise will issue Non Delivery Report (NDR).

b. GroupWise Side: for users planned to be  migrated from GroupWise to Exchange, Quest tool will configure forwarding rule that will forward all emails sent to to which reside on Exchange servers.

I’ve selected option 3 in my environment and the following steps explain the steps of how to configure in both environments:


Step 1: Configure Exchange with as shared namespace:

In Exchange we will need to configure the following:

1. Internal Relay Domain: the internal relay simply means that Exchange is not Authoritative (owner) of this domain, which means if the recipient email is not exist on Exchange it may be exist on another system (so no NDR will be generated).

The following article contains more information about the accepted domain:


The following snapshot shows how to configure Internal Relay Domain:



2. Create and configure Send Connector:

Create custom send connector with domain, make sure that the source server is the HUB servers (not Edge) and select “Route mail through Smart Host” this is should be the IP of the GroupWise server, if you will use CMG (Quest Co-existence Manage for GroupWise) then the IP should be the CMG’s IP.

3. Make sure that you have mail contact created for all users on GroupWise side, this is a mandatory step for the migration later, and can be done using Quest CMG (Co-existence Manage for GroupWise) Directory Connector or by import users to Active Directory using CSV file.


Step 2: Configure GroupWise Side:

When migrating a user from GroupWise to Exchange, one of the steps when using Quest tool “GroupWise Migration for Exchange” is to forward emails to Exchange account which should be


So the steps to configure GroupWise as follow:

1. Configure Smart Host: this step will configure GroupWise to send all emails send to particular domain ( to a specific IP, again if you will use CMG then this is the IP of the CMG server.

This configuration should be done through route.cfg file on the GroupWise server, this file location is domainqpgategwia, create the file if it’s not there.

Open the file in text editor and add the following line:

Where the IP is CMG IP or Exchange 2010 HUB. And restart the GWIA service (this is the service responsible of send/receive SMTP, similar to Exchange Transport Service)


2. Enable Flat Forwarding: in GroupWise the forward rule will send the email with from field from the user, example: user1 send email to user2, there is forward rule to forward all emails sent to to, all emails will go to Exchange side with from field from (very strange to Exchange guys like me :)). To present from field as the real sender of the message we will need to enable flat forwarding.

The following steps show how to do it:

a. Open ConsoleOne > Browse to GWIA > open properties.

b. Select SMTP tab > check to enable flat forwarding. As the following snapshot:



3. When migrating the user’s mailbox using Quest GME (GroupWise Migration for Exchange) you will select GroupWise Administrative functions > select set forwarding from GroupWise to Exchange.


4. Step 3: Testing:

Send emails from Exchange to GroupWise and vice versa.


This article explained the main challenge which is co-existence, in the next articles we will discuss some of the migration problems that may happen during Step 5: The migration.