How to Modify header


New Member
We want to know the option to change the header so we can remove the system domain name?
System domain = main site on which mailwizz hosted.
Customer= Running their own transactional server want to send email from their provider.

Say customer A using his mail servers to send email but in header shows system domain for

1. x-report
2. x-ebs
3 list-unsubscribe
How can we modify it or remove it?