Relevant Products: Exclaimer Cloud - Signatures for Office 365
A user is unable to send email and the error below is received:
This error occurs because Office 365 has banned the user from sending email, because they are deemed to have sent excessive levels of outbound spam.
A user can be de-listed as per the guidance in this article.
Handling a compromised account
To resolve a compromised user account:
- If you are an administrator, see guidance in this article
- If you are a user, see guidance in this article
You can configure Office 365 to send notifications when outbound spam mail email is detected, or if a user has been banned by Office 365. To do this, update Outbound Spam Preference settings in the Exchange Online Admin Console, as per this article.