A user is unable to send an email and receives the following error:
For more information, see how to Remove blocked users from the Restricted Users portal in Office 365.
Handling a compromised account
To resolve a compromised user account:
- If you are an administrator, see How to fix a compromised (hacked) Microsoft Office 365 account.
- If you are a user, see How to determine whether your Office 365 account has been compromised.
You can configure Microsoft 365 to send notifications when an outbound spam email is detected or if a user has been banned by Microsoft 365.
To configure the notifications:
- Update the Outbound Spam Preference settings in the Exchange Online Admin Console as per the instructions here: Configure outbound spam filtering in EOP.