When you end the turn a file is created in the savegames folder of that game, it should say something like eg. early_Mictlan.2h file, you take that file E-mail it to the other person than he puts it in the game folder, hosts the next turn, and send you back your early_mictlan.trn, you copy it back to the game folder and so on.
The same like Llama server.
I'm not sure I explained this good here is the link to Llama's FAQ how to do it.
http://forum.shrapnelgames.com/showthread.php?t=35160