Domain Management

Hello: I manage many WP websites for clients. Is there a way to access them all from one login? I thought it was domain mapping but it does not seem to work the way I want.

Now that I am using the supported plugin I want to have all my clients to be easily managed by us.

- I would like to access them through one interface
- Provide maintenance and updates
- Offer specials through supporter plugin

Is this possible?