PBEM: Failed to connect to server (timeout error) upon issuing challenge

[GeneraloberstYukariAkiyama]

Hi, I'm trying to issue a challenge to play against a friend in PBEM. Specifically I'm trying to run the World at War 1941-1945 scenario by ajs81 within the PAK mod, the game will try to load it for a little bit until I get the classical time out error (failed to connect to server). I realize the scenario is rather big and its enormous size is probably what causes the time out but I wonder if there's a workaround I can try. I already tried the nocache setting in the hope it could load more easily and all it did was prolonging the waiting time with the same end result.
Anyone can help me? Thank you.