Public Folder Migration from Exchange to Office 365: A Step-by-Step Guide

With transition to Office 365, you would be using more of Microsoft 365 Groups, which would include emails, calendar, contacts, and documents (using SharePoint Online). In addition, you can integrate other cloud applications and communication tools, such as Microsoft Teams, with Microsoft 365 Groups. Although you would be moving to a new setup, public folders in Office 365 are still widely used for their features. So, you should consider migrating the public folders from Exchange Server to Office 365.

In this article, we will be talking about the need of migrating public folders to Office 365 and will be discussing different methods to migrate public folders from Exchange to Office 365.

Why you Need to Migrate Public Folders to Office 365?

Migrating from a local Exchange Server to Office 365 is a strategic move for companies to shift to a cloud-first strategy and to move away from end-of-life server systems. In certain companies, the tools of the new setup are introduced slowly to the users for a few reasons, such as:

• Smooth and seamless migration to new tools.

• To not get resistance from the users.

• Plan the design of Groups and Teams.

For this reason, you wouldn’t just migrate away from public folders. These would need to be migrated to Office 365 in the interim, until the shift is complete.

Methods to Migrate Public Folders from Exchange to Office 365

Unlike user mailboxes, there isn’t a straightforward method to migrate public folders. But we will discuss a few methods that you can use to migrate the data of public folders to Office 365.

1. Using the Export/Import Feature in Outlook

You can manually export public folders using Microsoft Outlook to a PST file and then import it into Office 365. For this, you need to setup a profile in the application and must have full access to the public folders you need to export. The next step is to setup the destination mailbox - be it a shared mailbox or Microsoft 365 Group. You can then import the PST file into the destination mailbox using Outlook.

Pros:

• There is no need for scripting and complexity when it comes to the procedure.

• This method is useful for exporting very small public folders.

Cons:

• It is an administrative burden to use such method for large public folders.

• As there is manual intervention, there are several points of failures.

• No continuation if the process is stopped.

• Outlook may crash while exporting/importing large public folders due to its processing limitations.

• No reporting and no automation.

• There is a high risk of data loss or corruption.

2. Using Migration Batches

This method is somehow automated with minimal manual intervention. Rather than having the export and import procedure, you can use migration batches to seed the data from the local Exchange Server to Office 365. Once the seeding is done, you need to complete the process and cutover to the cloud. Although this process looks easy, you should note that there are a number of scripts and pre-migration tasks that you need to do. Let’s look at the prerequisites of this method.

• Have the right permissions in the Exchange Server and Office 365.

• Do an inventory of the public folders and remove any special characters from public folder names.

• Ensure that the public folder size does not exceed the 5 TB size.

• Make sure that the Exchange Server is fully updated with the latest Cumulative Updates (CU).

The first thing is to download the Public Folders Migration Scripts from the Microsoft website. These are PowerShell scripts.

The next step is to prepare the local Exchange Server environment by running the folder statistics scripts, which would also generate the CSV file to map the public folders with the cloud counterpart. After this part is done, you should proceed to create the public folders on Office 365 to match the local public folders.

Once this is done, you need to create and run a migration batch, which will seed the data from the local Exchange Server to Office 365. Once the process is done, you should first lock the local public folders to prevent any more changes and run the complete procedure to affect a final sync. Once this is done, the process will unlock the Office 365 public folders and the users can use them.

Pros:

• This method is officially supported by Microsoft.

• Ideal for small to large companies with large number of public folders.

• It does maintain the folder hierarchy and permissions post migration.

• It reduces the administrative effort from the IT team, but would require scripting skills.

Cons:

• This method would require scripting skills.

• Since there are various scripts, there is a higher chance of human errors

• The process can get quite complex and lengthy.

• Depending on the business and the public folders size, the process would result in downtime during the final synchronization.

3. Using a Specialized Exchange to Office 365 Migration Tool

With the above two native methods, there is a considerate number of challenges you might encounter. When it comes to data migration, the top priority is to have a smooth and seamless process with complete data integrity. With specialized Exchange migration tool, such as Stellar Migrator for Exchange, you can achieve this.

With this tool, you can migrate user mailboxes, user archives, shared mailboxes, and public folders. It offers pre-migration analysis, with real-time and post-migration reporting. It also supports delta (incremental) migration of data. In addition, there is minimal downtime and no risk of data loss. The tool supports all versions of Exchange Servers. Since this is a third-party tool, the only con is the licensing cost.

Comparing the Three Methods

Below is a comparison of the above three methods based on different factors.

 Conclusion

Above, we have discussed different methods for the migration of public folders from Exchange to Office 365. When it comes to migration of data, there has to be a smooth/seamless process and data integrity will ensured. This is why you should be very careful to which method to use for the migration of data. The specialized migration tool – Stellar Migrator for Exchange – can migrate public folders from Exchange Server to Office 365 with minimal impact and migration effort. So, the admins can focus on other things, such as data governance and security access and accounts.