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MAILCONGRAPH - Microsoft Graph API Request Failed

Fix this error by refreshing authentication and checking the Azure app permissions for Microsoft 365.

MAILCONGRAPH appears when the Microsoft Graph API rejects a request from ServiceOps for the configured Microsoft 365 mailbox. This typically means the Azure app permissions are missing or the Client Secret has expired. Use this page to re-authenticate and restore Graph API access.

Error CodeMAILCONGRAPH
Error MessageMicrosoft Graph API request failed. Verify the app permissions and try re-authenticating.
SeverityHigh
AffectsIncoming and Outgoing Email Servers (Microsoft 365 / Graph)

Symptoms​

Look for these signs to confirm this error is active.

  • Email sync or sending via a Microsoft 365 account configured for Graph API fails.
  • The error references a failed Graph API request.

Root Cause​

One of these conditions caused the Graph API request to fail.

  • The Azure application is missing required mail permissions (for example, Mail.Read or Mail.Send).
  • The Client Secret configured in ServiceOps has expired or been regenerated in Azure.

Resolution​

Follow these steps to restore Microsoft Graph API access.

  1. Enter the password again and save the configurations on the server card, then complete the Microsoft sign-in.
  2. Check whether the Client Secret has expired in Azure. If it has, generate a new one and update it in the ServiceOps email server configuration.
  3. If the issue persists, contact your Azure Administrator to check whether a conditional access or compliance policy is blocking this application.
Related FAQs

See Email Server FAQs for: "Why did the OAuth incoming server suddenly stop fetching emails?" and "Why did the OAuth outgoing server stop sending emails after working fine?"