ArGoSoft Mail Server Freeware
Full user review
"Great Little Mail Server"
This was the perfect solution for my small company internal email server. I was up and running in minutes and the support was also quick - were do you get that for a freebie? Great product.
Think the developer needs to emphasize more the critical need to be sure if you use the "Open Relay" be sure you also select require Authentication.
In WinXP I for some reason have to close it using task manager as it will not close by using the exit button.