In 1996 I wrote a tool for Microsoft that automated the management on NT 4.0 user accounts and Exchange mailboxes. This was before the days of the Management Console... If you are using NT 4.0 and Exchange 5.0, you can download it and use it here. Here is the readme. The tool's UI was built using Visual Basic 3.0 and the core DLLs that interfaced with the Win32 security and Exchange API's were written in C.
My goodness... those were the days.