Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
Hi @I365
Based on your description, I have tested the scenario on my side and can confirm that I am seeing the same behavior when adding Microsoft 365 (Office 365) accounts to the Gmail mobile application.
From my findings, this does not appear to be caused by incorrect credentials, MFA settings, or app password configuration. I also found that other users have recently reported the same issue with the Gmail mobile app when connecting to Exchange Online accounts, showing the exact error message you mentioned.
There are indications that this is related to a recent compatibility issue between the Gmail mobile app and Exchange Online, where authentication fails even though the same account works correctly in other clients. In particular, users have reported that Outlook mobile works without any issue while the Gmail app fails to authenticate or repeatedly rejects valid credentials.
Currently, there is no official confirmation or fix announced from Microsoft or Google regarding this behavior. Based on current findings, this appears to be a service/client-side issue rather than a tenant configuration or user account issue.
As a workaround, affected users should continue using the Outlook mobile application or Outlook Web to access their mailbox, as it uses a different authentication and sync mechanism and is not impacted by this issue.
You can read more at Gmail app bug locks some Microsoft 365 and Exchange Online users out on Android, Outlook still works.
This information is provided as a convenience to you. These sites are not controlled by Microsoft, and Microsoft cannot make any representations regarding the quality, safety, or suitability of any software or information found there. Please ensure that you fully understand the risks before using any suggestions from the above link.
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.