Currently, the e-mail notifcation upon account creation is really designed for the global server administrator, not domain administrators or resellers. It is configurable only in the "new e-mail" templates now, but it should also be configurable in the virtual server and reseller account creation forms.
In other words, when Virtualmin was first created, there used to be only two people interested in notification of new e-mail accounts: the end user and the server administrator. Now, there are potentially up to 4 people, in order or priority: the end user, the domain (virtual server) administrator, the reseller, and the global server administrator. Note that the server administrator, which is who is still notified now, is the least likely of these 4 people to still want these notifications any more.
In particular, my recommendation is that the CC field for new e-mail account notification should go to the domain (virtual server) administrator account by default, and there should be a new BCC field that optionally goes to the reseller and/or the global server administrator. Ideally, these should all be customizeable, but I think most administrators will want to keep the defaults I just described.