3681091 - Outlook Integration Not Working When Using Basic Authentication (EWS API – End User Sign-In) in SAP C4C

The user has configured their email settings in SAP Cloud for Customer (C4C) with Microsoft Exchange basic authorization (EWS API) – End user sign-in, but the connection status remains Not Connected. As a result, the Outlook integration does not work, and emails are not synchronized.

SAP Cloud for Customer

1. Log in to SAP Cloud for Customer (C4C).
2. Navigate to the E-Mail work center.
3. Go to E-Mail Integration or Groupware Settings.
4. In Groupware Settings, search for the affected user in the Users section on the right-hand panel.
5. Select the user and open the facet E-Mail Configuration.
6. Verify that the Mailbox type is set to Microsoft Exchange basic authorization (EWS API) – End user sign-in.
7. Observe that the connection status shows Not Connected even after entering the credentials.
8. Attempt to access Outlook integration, and notice that the synchronization and add-in are not working.

Microsoft has deprecated Basic Authentication for Exchange Online and other Microsoft 365 services.
When using the Mailbox type Microsoft Exchange basic authorization (EWS API) – End user sign-in, the authentication request is blocked by Microsoft’s security policies.
As a result, SAP Cloud for Customer cannot establish a connection with the user’s mailbox, and the status remains Not Connected.
This issue affects all tenants still configured to use Basic Authentication instead of OAuth 2.0.

1. Log in to SAP Cloud for Customer.
2. Navigate to the E-Mail work center.
3. Go to E-Mail Integration or Groupware Settings.
4. Search for the affected user in the Users section on the right-hand panel.
5. Select the user and open the E-Mail Configuration facet.
6. Change the Mailbox type from Microsoft Exchange basic authorization (EWS API) – End user sign-in to Microsoft 365 OAuth (EWS API) – End user sign-in.
7. Save the changes.
8. Once saved, a Microsoft login window will appear. Enter the user’s Microsoft 365 credentials and grant the requested permissions.
9. After successful authentication, the connection status should update to Connected.
10. Verify that the Outlook synchronization and add-in are now working properly.

• OAuth 2.0 SAP
• Overview of permissions and consent in the Microsoft identity platform
• Authentication and authorization basics in Microsoft Graph
• Application and delegated permissions for access tokens in the Microsoft identity platform

outlook integration; sap c4c; groupware settings; email configuration; microsoft exchange; basic authentication; ews api; end user sign-in; not connected; exchange online; microsoft 365; oauth 2.0; authentication issue; deprecation; email sync; outlook add-in; connection failure; office 365; azure ad; migration to oauth; login prompt; authorization error; c4c email setup; exchange connection; user mailbox , KBA , LOD-CRM-GW-OUT , Outlook , Problem