Digital Game Support
Step 1 - Select your Game: Memoir '44 Online
Step 2 - Select your Version: Steam/PC
FAQ / Customer Service / Support
Memoir '44 Online: How should I configure my Firewall?
Memoir '44 Online needs to connect to our servers. You should allow it to open connections : add an exception to allow Memoir'44 Online on any address and any port, and it will be fine.
If you want to limit the opened ports to the minimum, required ports are: 80, 443 and 9598.