UnknownIncomingEmailIntegrationError -2147220970 exception appears in Microsoft Dynamics 365

This article provides a resolution for the UnknownIncomingEmailIntegrationError -2147220970 exception that occurs in a Microsoft Dynamics 365 mailbox record.

Applies to:   Microsoft Dynamics 365
Original KB number:   4471947

Symptoms

The following warning level alert appears within a Microsoft Dynamics 365 mailbox record:

An unknown error occurred while receiving email through the mailbox [Mailbox Name]. The owner of the associated email server profile [Profile Name] has been notified. The system will try to receive email again later.
Email Server Error Code: Exchange server returned UnknownIncomingEmailIntegrationError -2147220970 exception.

Cause

This warning may appear if Server-Side Synchronization attempted to retrieve emails but encountered an unexpected error. This is typically a temporary issue and the emails will be retrieved successfully on the next synchronization cycle (typically 15 minutes).

Resolution

If this message does not persist on the next synchronization cycle (typically 15 minutes), this warning can be ignored. If this message persists, you can contact Microsoft Support.