I ask this because I recently picked up Battle Academy 2 from Matrix and saw how their PBEM++ system works.
Just imagine if you could fire up Combat Mission, hit multiplayer, create a nice little meeting engagement of size and type to your liking, post it, then wait until you get an email letting you know it's your turn to play! This is how Battle Academy works and it's awesome. You can browse games posted by others, decide on one that suits you and one-click later you are playing.
I haven't played CM multiplayer in over a year, but last I checked it involved using Dropbox and a third-party program to handle moving files around for you, which I suppose is convenient enough, but still feels clunky.
Not to mention, in BA you can browse and download new community scenarios from within the game.
I know this is unlikely, but just something to think about. I wonder if they could just lease the whole system from Matrix?
Edit: And before anyone says "Most people don't play multiplayer so it shouldn't be a priority" I would pre-emptively counter that by arguing that few people bother with multiplayer because it's a PITA to setup and play.