Small Business Server 2000 ?

SBS 2000 is the best package for the small business that doesn't require advanced technical knowledge. It is indeed possible to replicate the functionality of SBS 2000 with a Linux server, but you need to be a very strong Linux admin to be able to pull it off well. SBS puts a shiny interface on the process of managing a server, and does it well. Combined with Windows on the desktops, SBS packs a powerful punch for productivity. We use it exclusively for our small business clients.

Regards,
Chris