Having a problem with Magento 1.7. Order confirmation emails are being sent, and customers receive them. Shipment confirmation emails are being sent to the bcc: address, but customers do not receive them.
I've tried changing the BCC settings to both BCC and Separate Email and the result is the same for both.
There is noting relevant in system.log or exception.log. Does anyone have any suggestions? I don't even know where to look at this point, I'm completely baffled as to how the order conf emails are going out but the ship conf aren't.
The only difference I'm aware of is that the shipment is being fulfilled by a third party, and the shipment records are being created via the Magento API.