All mail sent from StarChapter systems will have a "from address" of [email protected], where domain.ext is your organization's domain name. While the @mg.domain.ext is requirement to meet authentication requirements set by major email providers and ensure better email delivery, the "postmaster" portion of the email address and the Sender Name can be customized to better identify your organization's mail to recipients.
Update From Address
Go to Communications > Settings > General (tab).
Update the "Send outgoing emails from" field to replace the "postmaster" portion of that email address.