We are migrating to a new customer support ticketing system (desk.com) and unfortunately while moving over our old tickets the new system (Zendesk) sent an auto reply to "new users". We weren't aware this would happen and so and email was sent out in error.
You do not need to create an account and you can ignore the email entirely.
You can find more info about this over on our forums here: https://forums.kleientertainment.com/forums/topic/110413-zendesk/
Sorry for the confusion
You know in the comic how Wilson is building that portal thing? Maybe you have to do that in singleplayer in order to play multiplayer. That would be interesting. Trying to get your friends far enough into the game to build the portal and all of that. Especially if they are new to the game.