I am looking for something Microsoft's Small Business Server 2003.

I am looking for email - similar to Exchange and some sort of
groupware - where people can collaborate on a project. Where I can
add create project groups for specific clients. Keep this separate
and organized.

SBS laid it out nicely in terms of what I want. Price and skepticism
about MS (too many patches and susceptibility to attack) have held me

Does anyone have any experience with this. An MS alternative.