dymanic IP, theoretically possible, but not very legistically, at least not easily, unless at a specific time you needed something, you could tell someone to send something to email@example.com
Free mail servers... Try sourceforge, see if they have anything for a w32 system, havent' looked myself, but people often don't check sourceforge, they think it's all linux stuff, but I have found quite a few good windows programs there, or at least programs that have been ported to w32
setting it... RTFM... no, seriously, there should be some faq's about it, you'll have to open up the appropriate port numbers if you have a firewall, perhaps 25 or 110.
Ep, glad to see you come back and tidy up...did want to ask a one day favor, I want to enhance my resume , was hoping you could make me administrator for a day, if so, take me right off since I won't be here to do anything, and don't know the slightest about the board, but it would be nice putting "served administrator osnn", if can do, THANKS