Interested to have a true Gmail account but will carry your own domain for emails? Add in a Calendar, Chat interface, a web based office suite and a lot of other Google goodies ideal for work environment or for personal productivity and you have a very rich integrated web apps.

Google Apps Admin Dashboard
Here is a quick setup guide for you! The free standard edition though would only carry a limit of 50 accounts (as far as I know)- good enough for small companies I guess.