Hi, @Qbit Global Admin
Based on your mô tả tìm kiếm, I understand that you are experiencing an error message associated with your tài khoản when deleting a group thư mục.
1.Check again if the tài khoản in the EAC was successfully removed.
2.Can you see the group thư mục in OWA?
Here are some steps you can try.
1.In Outlook, click the File tab in the top left corner.
2.Click on Account Settings and then select Account Settings from the drop-down thực đơn.
3.If you want vĩ đại remove the thư mục, make sure that it's not mix as the mặc định tệp tin. If it is, you'll need vĩ đại mix another tệp tin as the mặc định first.
4.Select the tệp tin, and click Remove if you no longer need it.
5.Close the Account Settings window and restart Outlook vĩ đại see if the issue is resolved.
If that doesn't work, you can still try removing full access vĩ đại the mailbox.
You can use command
Add-MailboxPermission -Identity -User -AccessRights FullAccess -InheritanceType All -Automapping $false