Exchange Backup Jobs Warning "Failed to find group owner account"

Challenge

Backup jobs with Microsoft Exchange items may end up with the warning message shown in both the Veeam Backup for Microsoft Office 365 console and the Veeam.Archiver.Proxy.log file.



1/20/2020 6:30:28 AM   62 (2600) Resolving group: 753da553-b4dd-45ad-a773-180aa920c887:00000000-0000-0000-0000-000000000000...
1/20/2020 6:30:28 AM   62 (2600)   Group found: TestOwnerGroup
1/20/2020 6:30:28 AM   62 (2600)   Resolving group mailbox (ID: 753da553-b4dd-45ad-a773-180aa920c887:00000000-0000-0000-0000-000000000000)...
1/20/2020 6:30:29 AM   62 (2600)     Found group mailbox: testgroup@organization.onmicrosoft.com
1/20/2020 6:30:29 AM   62 (2600) Warning: Failed to find group owner account

Cause

Impersonation is not possible if Office 365 groups (mail-enabled and security groups) do not have an owner.

Solution

Make sure to assign an owner to each of the Office 365 groups (mail-enabled and security groups) as described in this Microsoft article.