As an ISP, I host many company domains that provide email accounts for my customers. Each customer gets 5 email accounts as part of our service, and they can select from any of the company domains we host. They can also buy their own virtual domain, but that's another topic. It would be very useful if I could create one new email address for the primary account holder, and then that account holder would have the ability to create and manage up to X more email addresses in one or more of my company domains.
The primary account holder would not be able to see/modify other email addresses in the company domains, but they would be able to fix their wife's or kids passwords. You could have a range of options in the domain template that could be delegated to the primary account holder. We could delegate just the ability to reset passwords, or we could also allow the account holder t o create and delete sub-accounts, and a bunch of other options I haven't thought through yet.
I'm not looking for subdomains, but subgroupings of users within a single domain. The admin on my network should be able to easily see which email accounts belong to a particular customer. It can be as simple as adding an account code to each created user and allowing us to sort on it.
If the virutalmin server hosts multiple domains, the system should allow the option for the primary account holder to create his set of email accounts either in just one domain or selected domains or all domains. The admin should be able to exclude certain domains from the available list for privacy reasons.
If you got real fancy, you could extend the accounts across multiple VM servers hosting our domains. But that may be overkill.
I really could use the ability to see or manage the email accounts specific to a single customer account. Allowing the user to self manage would be a plus.