I recently created my first reseller account and I found a few things I believe would be nice to have.
If the reseller package allows for app installation, Resellers should be able to select what app to auto install in their packages. This is currently not possible, and this value is inherited and blocked.
Resellers should be able to set mailbox number, sizes and type. Right now, these values are inherited from the reseller package.
If the main account set mailbox sizes to unlimited, or a >0 number, Resellers should be able to set limits from 0 to that number or unlimited.
Ability for resellers to set their custom smart host.
Ability for resellers to set their custom smtp for transactional emails.
Transactional emails should be sent from the resellers support email, enhance currently uses the main account's email address, so no white label experience. (this is something someone else also suggested).
Ability for the Reseller to set hard disk limits for their customers, inside the boundaries of their own reseller package.
If someone else is using the reseller functionality, please to add your own suggestions.