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A successful Exchange migration project is not only measured by the migration of data, but also by the design strategy of the company when it comes to long-term goals, such as security, compliance, and integration. Therefore, it is crucial for a company to plan the migration properly, especially when it is a large-scale migration for enterprise environments. If the migration is not planned well, then the repercussions can be catastrophic.
In this article, we will be discussing how to plan a local Exchange Server to Microsoft 365 migration, in particular for enterprise environments. We will also be discussing the challenges that you might face and how a professional Exchange migration tool can mitigate these challenges and provide a seamless and smooth migration to Microsoft 365.
How to Plan Large Scale Exchange Migration for Enterprise Environments?
Planning a large-scale Exchange to Microsoft 365 migration for an enterprise environment requires a structured approach that will ensure minimal downtime and complete data integrity. Here is a comprehensive plan that you can follow for managing a large-scale Exchange migration.
Establish Business and Technical Objectives
First, you would need to establish the purpose of the migration project. You would need to provide a business case to the company where moving to Microsoft 365 would reduce the costs and benefit the company.
The key business drive would be the reduction of data center Capital Expenditure (CapEx). In an on-premises Exchange environment, you would need to spend a lot of capital on storage, compute, maintenance, and disaster recovery sites. On the other hand, when you move to cloud, there is only Operational Expenditure (OpEx), i.e., you will pay for the things you use. Thus, it will help reduce the overhead of equipment and maintenance costs.
You should also consider the benefits of collaboration tools, integrations, and standardization across the company. In big companies, this is the key for control and maintenance of the system as well as increased security posture with the Microsoft cloud security stack, which can bring a number of controls and conditional access that will simplify compliance.
Assessment of the Current Environment
This is a crucial element in the planning of migration. Apart from having an inventory of the current local infrastructure, including mailboxes, users, connectors, devices, resources, sizes, and other technical information, this process will uncover hidden risks, technical requirements, and other dependencies the system would need to have.
Exchange Infrastructure - You would need to optimize the local infrastructure to ensure that the Exchange Server Cumulative Updates are installed with patch level. All the required server roles are installed and the health of databases is proper, with the public folder usage, transport rules, connectors, and custom connectors. Journaling might be an issue when going to cloud as there is online archive. Also, there are some size restrictions/limitations when it comes to resources.
Identity and Authentication – If the company would go server-less and cloud-first, you would need to consider the local Active Directory health, domain forest levels, UPN (Address) consistency, or un-routable domains. The Active Directory would be ready for synchronization using the Entra Connect for hybrid systems. When it comes to identity and protection of the identity, there are a number of things that need to be planned for Microsoft 365. These include device or connection compliance, conditional access and Intune. Not having the right authentication controls can lead to security concerns and regulatory compliance issues.
Cleanup Process – In large enterprises, there will be several resources that are created, deleted, and left there. So, once the inventory of all the resources is complete, you would need to evaluate the size limit, what data will be migrated, and if the resources will be migrated or converted to Microsoft 365 Groups, Shared Mailboxes, or distribution list. This is a very important task as after this is complete, the licence requirement document will be drafted. Since all the licenses in Microsoft 365 comes at a cost, it will make a big difference for a large company if wrong licenses are purchased and assigned to the resources.
Deciding the Data Migration Strategy
Once a plan is decided with the design in hand, the biggest struggle that many companies face is deciding the right migration method. For migration of data, these are the options.
Staged Migration – This method is supported natively. In this, you can have a set of migration batches with a number of mailboxes that are staggered and seeded until a cutover migration is complete. Although this might seem one of the right methods to use, you must take into consideration that it doesn’t offer coexistence. So, there might be issues with free/busy sharing and other delegations of the calendar, while the administrators would need to recreate all the user Outlook profiles.
Hybrid Migration – This is the smoothest and seamless native migration method since it combines the local server and Microsoft 365 as one environment. With this method, you can have coexistence and users (on local server or cloud) can communicate seamlessly without issues. Although this might seem a great method, you need to consider some challenges that you might encounter. There is complexity of the setup of the Hybrid Connection Wizard (HCW), the Entra Connect for password synchronization, and the Exchange Server configuration.
Both native methods do not support cross-forests and public folders would require special handling due to their size and a number of legacy restrictions.
Specialized Exchange Migration Tools – Another option is to use specialized Exchange migration tools, such as Stellar Migrator for Exchange. This tool can overcome the limitations of staged migration and complexity of having a hybrid system. It supports migration of user mailboxes, shared mailboxes, archives, and public folders from any version of Exchange Server to Microsoft 365 with automatic mailbox matching. It can also granularly migrate data to Microsoft 365. It provides incremental (delta) replication, real-time reporting, and post-migration reporting, thus ensuring migration success. This will relieve the migration team and they can focus on the design, preparation, security, and management of the system, while the migration is seamlessly managed by the tool.
Conclusion
Above, we have seen how important the planning is for medium to large migration projects. A migration can go very bad in so many ways. With the right planning, design, and assessment, you should have a smooth migration from Exchange to Microsoft 365. With the specialized Exchange migration tool, such as Stellar Migrator for Exchange, you can seamlessly migrate the data from an Exchange Server to Microsoft 365. This tool also facilitates data migration from Exchange to Exchange, Microsoft 365 to Microsoft 365, and Microsoft 365 to local Exchange.
