You can view the player list by using the menu from the game screen and selecting Menu>Alliances and Players>Player List. The player list can be sorted by player name or points. To search the player list, simply start typing some of the letters in their username. For example, you can type "tha" and "Ethan" will appear in the list. Also, you can search players by their alliances. Clicking the "Allies" button will show only players in your alliance, and clicking the "My Sectors" button will show only players in your sectors.
There are several ways to send a message to a player. From the player list, select a player to open a screen for composing a message. Alternatively, zoom in on a fleet or building, and select the "Hail Owner" button. If the player has created an alliance, you can send a message to that alliance. Finally, when viewing a message, you can select the reply button.
If you receive a message from a player, you will receive a notification in your email and in the game by default. You can change this in Menu->Preferences.
Alliances are essential to prospering in Space. Alliance members can see each others' fleets and planets, and can see any fleets or planets that their allies can see. Your fleets and buildings will not attack your allies' fleets and planets. You may only be in one alliance at a time. Alliances will be ranked by points, but the alliance with at least half of the open planets wins the game. If the game takes too long, the game may be ended manually, and the alliance with the most points will win.
To start an alliance, select “Alliance Management” from the menu when in the game view. Then, choose the option to create an alliance. Give your alliance a name.
To invite players to your alliance, send them a message. If you are the leader of an alliance, you will have an option to include an invitation in your message. If they accept your invitation, they will be added to your alliance.
To be able to join an alliance, the alliance leader must send you a message with an invitation. If a message contains an alliance invitation, when you view the message, there will be an option to accept the invitation. If you accept the invitation, you will be added to the alliance unless you're already in an alliance, the alliance invitation expired (3 days after it was sent), or you already used the invitation (if you join an alliance, leave it, then accept the invitation again, you won't be accepted.)