Most of the Exchange administrators struggle when it comes to a smooth and seamless migration to Microsoft 365. In this article, we will go through the most common things that you should look for when migrating from a local Exchange Server to Microsoft 365. We will also mention a reliable Exchange migration tool that can ensure a successful and smooth migration of mailboxes to Microsoft 365.
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Best Practices for Seamless Mailbox Migration to Microsoft 365
Let’s take a look at some best practices you can follow during and post Microsoft 365 migration.
1 – Planning
First things first! Planning is the most crucial element for a successful migration project. Without good planning, the project can go over-budget, fail catastrophically, disrupt the services, and affect the business. This can lead to a lot of issues to the business operations. If there is missing data, corruption in data, or disruption to the service, this will make the business suffer. The projected plan will have information from the finance part of the project, resources, deadlines, and other information for a successful migration. You should have all the team’s information on the project, which would include network, server, domain/DNS administrators, and other stakeholders.
2 – Audit and Licensing
You cannot go ahead and purchase Microsoft 365 licenses without proper audit of the current data and the customers’ needs. Projects can fail if the wrong licenses are bought. So, before taking a decision with regards to what licenses to be purchased and assigned, you must go through an internal audit on the local mailboxes and have an inventory of all the mailboxes to be migrated. In addition, decide what will be migrated or not, and check the compliance regulations if data with a specific date can be migrated.
You can run the below command to have a list of all the active mailboxes.
Get-Mailbox -ResultSize Unlimited | Select-Object DisplayName, PrimarySmtpAddress, ArchiveStatus
You can use the below command to get the sizes of specific mailboxes.
Get-MailboxStatistics -Identity user@source.example.com | Select-Object DisplayName, TotalItemSize, ItemCount
Once a complete sheet is prepared, you would need to confirm which mailboxes to keep or discard and which mailboxes will be set as distribution group or converted to shared mailboxes. Depending on the size of each mailbox, you would be able to assign the correct license to the user.
3 – Decide the Migration Method
There are three methods which you can use to migrate data to the cloud. These methods would define the outcome of the project. Let’s discuss these methods.
- Cutover Migration
In cutover migration, data is migrated in a single migration batch. A date is set where the DNS records will be changed and the users will start using Office 365. After this process is complete, you would need to export the data from the Exchange Server and manually upload it to Microsoft 365. This is a manual operation and there is high level of error margin and hiccups. If a problem is encountered, there is a big struggle to failback to the Exchange Server.
- Hybrid Method
The hybrid method basically combines both the local and Exchange Online to work as one. The admin will create a move request to Exchange Online. After the data is seeded, you can easily complete the migration and the user will automatically switch their mailbox to Microsoft 365 with minimal intervention. This is the most seamless and smooth migration method. The only issue with this method is that it is complex to setup and daunting to troubleshoot when something is not working. Apart from this, it’s the slowest migration method.
- Using Third-Party Specialized Migration Tools
You should consider specialized Exchange Migration tool that can migrate user mailboxes, shared mailboxes, public folders, and user archives with ease, and real-time and post migration reporting. Stellar Migrator for Exchange can facilitate and provide a seamless migration. It supports the below migration paths:
- Exchange Server to Exchange Server (same or cross-forest/domain).
- Exchange Server to Microsoft 365.
- Microsoft 365 to Microsoft 365.
- Microsoft 365 to Exchange Server.
The tool is very easy-to-use and it doesn’t need any complex configurations. It helps with the throttling and migration, with its delta (incremental) seeding of data, automatic mailbox matching, folder specific migration, and seamless public folder migration, thus making the migration project effortless.
4 – Preparation of the Target Environment
When migrating to Office 365, the environment must be set accordingly with the domain verified and all the users are created with all the aliases assigned. The shared mailboxes need to be created with their respective permissions and forwarding.
This is not related to the mailbox per se, but the security aspect must be taken into consideration. You should consider multi-factor authentication, conditional access, and other security features to secure the tenant, once the migration is complete.
5 – Configuration of the Users
For a seamless migration, apart from the services and the data, you need to ensure that the switchover by the clients will be a seamless one. After the migration is complete and the new service is running, you need to ensure that all the users have accessed their online account and setup the multi-factor authentication. They’re provided with clear instructions on how to setup their account on their mobile device and the option of using Group Policy Objects (GPO). Ensure that Outlook client automatically detects the new mailbox using the Autodiscover records and follow the HTTP redirect by configuring the below path.
User Configuration > Administrative Templates > Microsoft Outlook > Account Settings > Exchange > AutoDiscover
You should avoid going through each and every user to setup the Microsoft Outlook profile, especially when having a large migration with users scattered all over the globe. Always try to automate the process for a smoother migration.
6 – Post Migration Tasks
After the migration of services and data, you should consider to decommission the local Exchange Server. Afte the migration, there could still be linking of local DNS records which could impact the access of users to the Exchange Online.
After removing all the mailboxes from the Exchange Server, including the built-in mailboxes, you should go ahead with the right procedure to uninstall the Exchange Server. This will clear out the Active Directory Schema from any Exchange Server configurations. After this is successful, you can go ahead with the disposal of the server or removal of the server from the hypervisor.
Conclusion
When moving to Microsoft 365, there are a number of tasks and steps you should consider before, during, and post-migration. Data migration is always the biggest headache. You should make sure to have the right tool in hand to facilitate the migration of data. Stellar Migrator for Exchange is a tool that you can rely upon for migrating user mailboxes, user archives, and public folders from Exchange Server directly to Microsoft 365.
