To resolve this issue, check whether forwarding rules are set up on the external mail account. If rules are set up, remove them. If no rules are set up, or if the issue persists after you remove the rules, manually remove the connected account. To do this, follow these steps:
- Connect to Exchange Online by using remote PowerShell. For more information about how to do this, go to the following Microsoft website:Note Only Exchange Online administrators can connect to Exchange Online by using Windows PowerShell.
- Remove the connected account again. To do this, run the following cmdlet:
Remove-Subscription <ConnectedEmailAddress> �Mailbox "<Office365EmailAddress>"
For example, if the email address of the connected account is <useralias>@hotmail.com and your Office 365 email address is john@contoso.com, use the following command:Remove-Subscription <useralias>@hotmail.com �Mailbox"john@contoso.com"
Note When you are prompted to confirm the removal, type Y to confirm this action. - Sign in to the Office 365 account again, and then confirm that the user is no longer receiving email messages from the connected account that you removed.