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 (email@example.com) Your message wasn't delivered because the recipient's email provider rejected it.
Diagnostic information for administrators:
Generating server: AS8PR01MB7606.eurprd01.prod.exchangelabs.com firstname.lastname@example.org 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.
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 https://protection.office.com/antispam