Stefano
AFAIK Centos 5.8 is not obsolete
Of course it isn't, generally speaking. I was merely referring to points 1 and 2 of my original post and, unfortunately, for me it is obsolete (for installing it on bare modern, fast, low-medium cost hardware). However, SME is still my best choice for installation in a narrow purpose VM (i.e. for email handling).
Actually I wonder why the SME distribution doesn't also come in the shape of a few narrow purpose, ready configured VMware virtual appliances ... I think it may gather more audience if people that don't know too much about Linux (still plenty of them) would get an easy chance to see how easy it is to configure and use.