I have a client with a new Exchange 2016 server. We setup a Distribution Group. Email sent internally to the Distribution Group are forwarded as expected. Email sent externally to the Distribution Group are never sent. Distribution Group is working for internal email addresses but not external email addresses.
I reviewed Delivery Management for the Distribution Group. "Senders inside and outside of my organization" is selected. There are no restrictions setup - "All senders can send messages to this group". Nothing is setup in Message Approval - no boxes are checked. What am I missing? Is there a global setting somewhere that's overriding the Distribution Group settings?