Migrating public folders ahead of EWS retirement: plan, prepare & perform

Microsoft has long signaled its plans to retire Exchange Web Services (EWS) in Exchange Online, with the phased EWS disablement beginning on October 1, 2026, and complete shutdown planned for April 1, 2027. From that point on, interactions with mailbox and calendar data – from migration and backup operations to third-party app integrations – will need to be handled via the Microsoft Graph API.

This shift is consistent with Microsoft’s push to turn Graph into a unified, cloud-optimized platform for managing Microsoft 365 data that consolidates older solutions (we covered this in more detail in this article). But it comes with some tradeoffs, too, as feature parity with those solutions is not always guaranteed.

Despite the initial lack of Graph support, public folder migrations will remain possible. Read on to learn what’s changing and how CodeTwo can help you migrate public folders to Microsoft 365.

Update (October 27, 2026): Microsoft temporarily disabled support for public folder migrations in the Microsoft Graph API to address some issues. As a result, public folder migrations to or from Microsoft 365 are currently unavailable. Microsoft plans to restore this functionality by the end of December 2026.

How EWS retirement impacts public folder migrations

Originally developed in the pre-Graph era, Exchange public folders rely heavily on EWS. Until recently, EWS was the only API that fully supported public folder migrations to or from Exchange Online. Microsoft Graph lacked the functionality necessary to support these migration scenarios, which raised questions about how public folder migrations would work after EWS retirement.

The good news is that the situation has changed. Our developers have been working closely with Microsoft to address functionality gaps between EWS and Microsoft Graph, including those affecting public folder migrations. Following feedback from CodeTwo and the wider community, Microsoft decided to add the necessary support to Microsoft Graph, ensuring that public folder migrations can continue after EWS is retired.

The latest versions of CodeTwo migration software already use Microsoft Graph and were released with support for public folder migrations. However, this functionality is temporarily unavailable due to changes introduced by Microsoft (see the update above).

How to migrate public folders to Microsoft 365

Note: The migration scenarios described below are temporarily unavailable in CodeTwo migration software due to Microsoft’s changes to the Graph API.

There are several ways for migrating public folder data to Microsoft 365, whether from an on-premises Exchange server or another Microsoft 365 tenant. The following two options tend to be the most practical in the majority of cases:

• Recreating public folders in the target environment – this way, you can migrate your public folder data and keep its hierarchy with as few changes as possible (along with the same drawbacks as before, including limited support on mobile devices). See this article to learn more about this migration scenario
• Migrating public folders to a Microsoft 365 shared mailbox – while this approach doesn’t preserve the original hierarchy across mailboxes, it fully supports mobile access, making it a popular alternative to public folders. See this article to learn more about this migration scenario

Which option should you choose, then? They both have their benefits and limitations. If your organization still relies on public folders and wants to preserve their existing structure, you can continue using them. Alternatively, migrating the data to shared mailboxes can be a good choice if you want broader client support, including access from mobile devices.

Plan, prepare, and perform public folder migration with CodeTwo

Whether you want to keep your public folders in the target environment or convert them to shared mailboxes, CodeTwo Office 365 Migration can help you plan, prepare, and perform the entire migration process with ease.

CodeTwo’s solution is a lightweight and intuitive desktop application for data migrations from on-premises Exchange Server to Microsoft 365 (Exchange Online), or between two Microsoft 365 tenants. The program eliminates the need for PowerShell scripting, ensures full data encryption, and automates the complex manual tasks required when using Microsoft’s built-in migration tools.

Going beyond the native solutions, CodeTwo Office 365 Migration helps you complete public folder migration with minimal time and effort. Using the application, you can:

• configure the entire migration process with just a few clicks,
• easily match your source public folders with either target public folders or shared mailboxes,
• run the migration according to a schedule (for example, outside working hours),
• specify which folder types you want to migrate,
• generate migration reports,
• migrate other data, including emails, contacts, or tasks.

Learn more about migrating public folders with CodeTwo Office 365 Migration

Try CodeTwo Office 365 Migration

To try CodeTwo Office 365 Migration in your environment, go to this website and test the application for 30 days at no cost. Free technical support is available 24/7, even during your trial.

Download CodeTwo Office 365 Migration and start preparing for your public folder migration today.

See also

How to migrate public folders to a shared mailbox