Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
Hello Harry Jackson1,
Good day! Thank you for posting to Microsoft Community. We are happy to assist you.
As per your given description, I have a general understanding. As per my general understanding, this problem occurs if Microsoft Exchange Web Services (EWS) is turned off in Exchange Online.
To enable EWS in Exchange Online. To do this, follow these steps:
1. Connect to Exchange Online by using remote PowerShell. For info about how to do this, seeĀ Connect to Exchange Online PowerShell.
2. Enable EWS in Exchange Online. To do this, run one of the following cmdlets, as appropriate for your situation:
- For a single user: Set-CASMailbox -EwsAllowOutlook $true -Identity "ONLINE USERNAME"
- For the whole organization: Get-Mailbox | Set-CASMailbox -EwsAllowOutlook $true
For more information, kindly refer this: Outlook for Mac 2011 doesn't connect to Exchange Online - Exchange | Microsoft Learn
If I misunderstand you, please feel free to let me know. I will continue to assist you. Your understanding and co-operation are highly appreciated.
Sincerely
Nafis Iqbal Shuvo