How to delete the "RECEIVED" headers from SMG?
SMG 10.9.0
It is possible to strip the "RECEIVED" headers for the outbound messages by navigating through the Control Center UI to Administration > Hosts > Configuration > Select your scanner > SMTP > Advanced settings > Outbound, then checking the "Strip pre-existing RECEIVED headers from outbound messages" option.
It's important to note that when headers are stripped, there's a possibility of message looping depending on the settings of other MTAs. In the other hand, leaving the option unchecked allows the "RECEIVED" headers to remain in the message during outbound processing.