Recently casual players using the Steam Client had been facing problems with receiving invites to groups that they were not interested in. These were mostly spam invites and would definitely pose a significant distraction to the players who were totally not interested in joining these groups.
Valve has addressed this problem in the best way they can. From today, you cannot invite a person to a group unless you are in their friends list. This ensures that there is a level of relevance to steam group invites. If someone is sending and spamming you with group invites, you can simply unfriend them and be assured that you will not get more group invites.
- Public group – Users can join on their own or via an invite from a friend.
- Restricted group – Users can join by requesting membership. They can also receive an invite from a user that has permission to add members.
- Closed group – This is the most restricted group. Users can only join via invites by members who have permission to send invites. Users cannot request to join these groups.
These new features and improvements should make it easier to join groups that you are interested in while eliminating the spam group invites that show up in your Steam inbox. Over the next few weeks, we’ll also be working on identifying and banning networks of groups that have been mass-created and exist for the sole purpose of spamming.
Source : SteamCommunity