In the Previous article the Microsoft 365 Tenant and Azure Active Directory Connect were set up. This article now deals with the installation and configuration of the Hybrid Configuration Wizard (HCW). The HCW creates the Exchange Hybrid environment and enables mailboxes from the Exchange on-prem installation to be migrated to Microsoft 365. The HCW performs all the necessary configurations on the Microsoft 365 tenant as well as on the Exchange on-prem environment.
Installation Hybrid Configuration Wizard (HCW)
The "Configure" button can be found under the "Hybrid" tab in the Exchange Admin Center, where the HCW can be downloaded, installed and configured:
During the installation of the HCW, it is necessary to log in to Microsoft 365 from time to time:
After logging in to the Microsoft 365 tenant, the HCW can be installed:
The HCW now guides you step by step through the hybrid configuration, which is self-explanatory in most places:
As there is only one Exchange server in my environment, I can only select this server as the "optimal Exchange" server. In environments with several Exchange servers at several locations, you could, for example, select the server with the fastest Internet connection. It is important at this point that the Exchange server selected here has a valid certificate from a public certification authority and is also accessible from the Internet. Microsoft 365 uses this server for the migration of mailboxes and for email routing. This Exchange server should therefore be accessible from Microsoft 365 via port 443 and 25; proxies, web application firewalls and SPAM filters can be somewhat problematic at this point:
In the next step, the login information for the tenant and the on-prem installation must be entered:
The HCW then collects the necessary data for the configuration of the hybrid environment:
The features can be selected in the subsequent dialog. If many mailboxes need to be migrated, the "Full Hybrid Configuration" is recommended, so that the scheduling assistant for displaying the free/busy times, for example, continues to work.
If there are only a few mailboxes and the plan is to migrate all mailboxes to Microsoft 365 in one go, "Minimal Hybrid" is usually sufficient. At this point, I select the "Full Hybrid Configuration" so that most of the features are available even for longer migrations:
The hybrid topology can now be selected; the HCW indicates here that the Exchange server requires an Internet connection and must also be accessible from the Internet under the configured URLs. The "Modern Hybrid Topology" allows free/busy times to be exchanged between Microsoft 365 and on-prem users:
In the next step, the login information for the local Exchange server must be entered again:
The next step is to install the HCW:
Configuration Hybrid Configuration Wizard (HCW)
Once the HCW has been installed, further details must be entered to configure the hybrid environment. As the Edge Transport Server is rarely used, the first point is probably the most frequently used:
The next two settings relate to the receive and send connector between the on-prem Exchange servers and Microsoft 365:
The HCW creates the corresponding receive and send connectors automatically:
A certificate must now be selected for email routing between on-prem and Microsoft 365. I use a valid certificate from Let's Encrypt here:
The last setting is the FQDN of the on-prem Exchange installation. This setting is about the routing of mails from Microsoft 365 to the on-prem installation, so the name of the SMTP domain is specified here, in my case frankysweblab.de:
The settings are now complete and the HCW can begin with the configuration:
The HCW now configures the on-prem servers as well as the Microsoft 365 Tenenat for the hybrid environment:
If the error message "HCW8077 - Tenant organization is dehydrated" appears after clicking on Update, simply wait 15 minutes and try again. The HCW normally sets the setting correctly, but it may take a while before it is active:
After approx. 15 minutes, the HCW ran through without any errors:
What happens next?
The next article will test whether the mails are routed correctly between Microsoft 365 and Exchange on-prem. The migration of mailboxes will also be tested. The necessary DNS adjustments are also part of the next article.