I use my laptop at work on wireless and wired networks, at home on a wireless network, and at various other places (such as conferences, friends houses, etc). When at work I'd like postfix to use the corportate mail server to route emails. When at home I'd like it to use my personal mail server to route emails. When elsewhere I'd like to have the laptop attempt to deliver email in the normal smtp fashion. Is this possible using just postfix? Do I need something else (such as Lamson http://lamsonproject.org/, or scripts that dynamically patch my postfix configuration) when I want to do routing that depends on my current location?