So my colleague Ben Donaldson and I have been working with one of our charity customers recently and had an interesting experience with their network appliance. This particular device was an all-in-one device that combined Firewall capabilities with Mail Hygiene and UDP Packet Inspection.
I went in and configured a hybrid Exchange Organisation with the customer’s tenant. When we came to test it, we had trouble validating the Outbound Connector from Office 365 to the local server. After engaging the firewall team in trouble-shooting, we were able to pinpoint the problem down to the Bounce Address Tag Validation or BATV within the appliance.
Once we specified the Office 365 Datacenter IP addresses as exceptions within the module, the emails were able to flow back and forth. So the moral of the story is to double-check just what devices are in the network path and whether they are all-in-one devices.
Next up, I’ll let Ben tell you about his experiences with the same network appliance.