I am using Xeams for DKIM, and set it as smarthost for exchange's send connector.

When I see the message header, I can see the internal IP of my mailbox sever as:

Received: from [(192.168.1.47)] by Xeams-VM with Xeams SMTP
192.168.1.47 is my mailbox server ip, Xeams-Vm is the host name for our Xeams server.

How can I remove or hide this?