Error: [Access denied, bad outbound sender]

Resolution

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.

Notifications

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.