Hi Jelle,
As I understand it, you have deployed SSO with Office 365 via ADFS + DirSync. And it does work fine since regular users can login to Office 365. However, you are encountering the issue that the admin account with the company.onmicrosoft.com suffix cannot login to Office 365 portal (http://portal.microsoftonline.com/) after enabling DirSync.
In such a scenario, I can understand the inconvenience while I’d like to collect the following information to try to help you:
1. Do you have any other Global Admin accounts with onmicrosoft.com?
2. Could you please share some information with us about “the account no longer exists”?
From my side, when I click the Can’t access your account link in the Office 365 login page
, I will be directed to the following page:
When I type in a non-exist Office 365 account, I will receive the following error saying the user ID doesn’t exist which is the expected result.
If it isn’t the scenario, please feel free to let me know.
@Steve,
Thanks for sharing the experience.
Best Regards,
Bruce Zhou