We have an external server that does some mail relay (legit) occasionally and part of its function is to send mail to large number of recipients as an authorized sender on the exchange server. Everything has been working just fine until recently. In the past mail would be sent from the relay server and then a BCC was inputed to BCC the sender of the messages a copy of the messages. Ex
userA emails 100 people through mail replay server and adds a BCC to UserA. All recipients receive their mail but the BCC recipient does not receive any of them.