If you use 
planet-save, you can save the rainforest with every e-mail! plus their servers are solar-powered. You can also get a free POP account 
here.
I don't use MSN because all of my friends are on AIM (and if they did, i'd try to get them to switch). For instant messenging, I use 
Fire (Mac OS X only), but 
gaim is also a popular multi-network client.
[ May 04, 2004: Message edited by: M51DPS ]