Two Office 365 accounts rejecting internal messages

Occasional Visitor

Our school Office 365 domain has about 35 users.


We have just discovered that 2 users are bouncing internal emails.  If anyone tries to send an email to either of the users they get:


Delivery has failed to these recipients or groups:

xx (
Your message wasn't delivered because the recipient's email provider rejected it.

Diagnostic information for administrators:

Generating server:
Remote Server returned '550 5.7.520 Access denied, Your organization does not allow external forwarding. Please contact your administrator for further assistance. AS(7555)'


I have checked both of the users accounts and neither have any mail forwarding set.  And it is only affecting these 2 users.


Does anyone know what might be going on?



1 Reply
Hi, this is most likely related to a new default setting in the outbound spam filter policy. It was recently announced via Message center. Go here for configuration

For more info