change the main domain of my virtualmin box


So I have 3 domains on my virtualmin box.

Currently is what appears as routing email from, and

I would like to make the active domain for sending email so that when an email is sent, it shows

How can this be done?

Thank you,



It typically shows your system’s hostname as the domain used when sending an email.

Is it an option to change your server’s hostname to “”?

You could also change the “myhostname” field in Postfix to “”, that should have a similar effect