How to identify customers that need to migrate from EWS to Graph API?

ApplicationImpersonation will stop working on Microsoft 365 Exchange service accounts from February 2025 which will stop EWS Service Accounts from successfully syncing M365 calendars. This will mean that customer connections not using Graph API by this point will stop working.

You will need to reach out to your customers to ensure that any customers using EWS apps that access Exchange Online migrate to Graph API before this date.

How to check which customers need to migrate their EWS application: #

To help identify which customers need to migrate their EWS application, we have introduced a graph_migration_status column to the Application Service Account Authorizations Report which will indicate if a customer needs to migrate and if so, if the migration is Pending or Complete. You can do this by following the below steps:

  1. Navigate to the ‘Developer’ portal for the application.
  2. Click on ‘Reporting’ on the left-hand side panel.
  3. Click on ‘Generate’ underneath the Application Service Account Authorizations Report section.
  1. Click ‘Download’ once the report has generated.
  2. You will see a column named graph_migration_status in the downloaded CSV.
  3. If any customers show ‘Pending’ in this column, they need to migrate to Graph API but have not yet migrated.

Are any EWS applications that do not need to migrate? #

Use cases that do not use ApplicationImpersonation will not be affected by this change, this includes:

  • Free-busy-only Enterprise Connect connections
  • Individual Connect connections

On-premise connections are also unaffected.

How can customers migrate from EWS to Graph API? #

Any customers that need to migrate can follow the steps in our FAQ guide. This will create a new Graph Service Account for their tenant which authorizes the same applications as the previous Exchange application.

This process works in much the same way as relinking someone’s calendar does. It only affects the link between Cronofy and the user’s calendar, with no impact on your connection as an integrator.