Hurricane Server automatically strips out any header beginning with X-xs by default. You can set a configuration file value to instruct Hurricane Server to remove other headers it finds in your outbound email messages by following the instructions below.
Edit the account level general.config, i.e. accounts\configgeneral.config
Find the [Other] section and add or edit the HeadersToRemove item. The value should be set to a comma-delimited list of the headers you wish Hurricane Server to remove from your messages automatically. See below for example.[Other]
PickupEnable = false
ClickTrackingEnable = false
OpenTrackingEnable = false
HeadersToRemove = BCC
3. Save the file and restart the Store service.