Next time it might be easier to use one of the direct connect servers instead of dropbox or pbem.
No fiddling with files at all, no downloading map.
www.Dom3Minions.com is one example
The idea of PBEM is to allow play on different schedules. Dom3Minions just looks like a way to play a TCP/IP game?
Either way, seems to be working fine for this game. When/if another game would be run, I was looking into Llamaserver.