To add more information. This will probably require about 10-15 minutes of each players time, maybe 1-2 times week depending on the number of players.
The game files will be transferred between players by attaching it to a main forum thread after you have competed your portion of the turn. That way the next guy grabs it, plays his part and replies, attaching the newly saved files with the team commander grabbing it last and posting for the the OPFOR guy (or me to process if using vs the AI) to do his part.
Each player will be allowed to post a 100 word reply with the attachment that will represent their radio traffic to the other players on what they saw, engaged, did during their part of the turn, etc. No other PM'ing and email allowed.