A hybrid deployment offers companies the ability to extend the functionality of an existing on-premises Microsoft Exchange to Exchange Online. This provides a single space between an on-premises Exchange organization and Exchange Online in Microsoft 365.

The following topology example provides an overview of a typical Exchange 2016 deployment. With a single-forest, single-domain organization with two domain controllers and one Exchange 2016 server installed, we start deploying and configure a required Entra ID Connect server and use the Entra ID Connect password synchronization feature to let users log in with the same credentials for both their on-premises network account and their Microsoft 365 account. Then we complete the hybrid deployment prerequisites and use the Hybrid Configuration wizard to select options for the hybrid deployment.

Your new topology will have the following configuration:

Users can log in to the on-premises and Exchange Online organizations with the same username and password ("single sign-on").
User mailboxes located on-premises and in the Exchange Online organizations will use the same email address domain.

All outbound mail is delivered to the Internet by the on-premises organization. The on-premises organization controls all messaging transport and serves as a relay for the Exchange Online organization ("centralized mail transport").

On-premises and Exchange Online organization users can share calendar free/busy information. Organization relationships configured between on-premises and Exchange Online also enable cross-premises message tracking, MailTips, and message search.

The same URL is used for the connection to mailboxes for both on-premises and Exchange Online users.

IT Partner responsibilities: #

1. Analyze the current Exchange On-Premises solution
2. Prepare the current configuration of Exchange and Active Directory for synchronization
3. Set up synchronization of users and passwords
4. Provide informational letters for users
5. Migrate mailboxes
6. Provide break-fix support related to migration issues

Client responsibilities #

1. Coordinate Client resources and staff schedules
2. Provide a dedicated point of contact responsible for working with IT Partner
3. Provide access to physical and virtual servers and/or systems and services as needed. Provide remote and/or physical access to facility and systems required to complete the work 
4. Configure workstations and mobile devices
5. Perform changes to internal and external DNS, as required
6. Assist with identification of high-risk users (top executives and VIP users, users with 50 GB mailboxes or larger and/or 30 GB deleted folders or larger)
7. Coordinate any outside vendor resources and schedules
8. Configure all network equipment, such as load balancers, routers, firewalls, and switches.
9. Review and approve engagement deliverables in a timely manner

Additional cost items not provided by the project #

1. Customer team training (could be added as an additional service)
2. Desktop software settings
3. Unified Messaging (US) features cannot be used in a hybrid solution in conjunction with Microsoft 365. If you use this feature in your infrastructure, additional settings can be required depending on the solution you are using.

Upon completion of the project, we will provide a project closeout report. This document will indicate the final project status, including acceptance criteria matching, outstanding issues (if any), and the final budget. If you require more extensive documentation, it can be provided for an additional fee. 

Prerequisites #

1. You must have a Microsoft 365 tenant with Exchange Online licenses
2. You must have access to your email domain DNS zone
3. You need a full installation of Exchange 2010, 2013, or 2016 server in your environment with a valid UCC SSL certificate

Plan #

The plan may vary depending on your needs.

1. Kickoff meeting
2. Pre-migration source system health check
3. Creating users or AD connect tool configuration
4. Migration planning
5. Email migration start
6. Email migration check
7. Changing MX record to the new Microsoft 365 tenant
8. Final email migration
9. Post-migration tasks

Success Criteria #

1. Users can access Exchange Online on their desktop PCs, mobile phones, and tablets from any place, any time
2. Mailbox data is successfully migrated to Exchange online and accessible to all users
3. All necessary transport rules are created and working
4. Mail can be sent and received using Exchange online
5. Exchange Online Protection is configured and working