Microsoft announced it would be discontinuing the Exchange Web Service (EWS) in Exchange Online (Microsoft 365). 
To ensure the interface between Exchange Online and JustRelate CRM continues to work through April 2027, you must explicitly enable EWS in your tenant and allow the Microsoft Entra app registration used by JustRelate CRM in your organization settings.

We are already developing an update to our interface. It is currently in the beta phase and is expected to be released in October 2026.
You are welcome to request a beta implementation for testing purposes.

We used these documents and information to assess the issue of the EWS shutdown and formulate our current recommendation

• Exchange Online EWS, Your Time is Almost Up
• Introducing EWSAllowedAppIDs: Preparing for the Final Phase of EWS Retirement

To use the the PowerShell on the local client you have to install the Exchange Online Module for PowerShell. 

If the value for EwsEnabled is NULL or False you have to set it to True

To retrieve existing IDs use the following Get-OrganizationConfig command

To set allowed ID use the following Set-OrganizationConfig command

It is not possible to add individual AppIDs to the list. The complete list must always be entered in the EwsAllowedAppIDs value.

Changes to the parameters may take up to 24 hours to take effect. This is because the Exchange Online in-memory cache is only updated every 24 hours.

To list all settings, load this information from the Exchange backend:

Important are the properties

• EwsEnabled = True
• EwsOperationAccessPolicyPopulated = True
• EwsAllowedAppIDs = <the AppID for JustRelate CRM>