I recently deployed two Barracuda Anti Spam solutions at a couple clients. They are linux based apparently, and run on inexpensive CPU's with little ram. What exactly hardware wise I am not sure other that when the unit boots and posts the BIOS info.
They are very effective but they ain't cheap.
Anyone know of a Linux based virtual appliance anti spam solution? Such as one I could run in a Virtual Environment and have it do the anti spam for me? Free preferred or near free.