Friends: in the "Friends" tab (or with /friend add name) you add up to 30 friends and decide per friend what they may do – e.g. open your code locks or be spared by your turrets. Team and clan count automatically. If a friend gathers near you, you both get +5 % yield. For every friend you see whether they are online or when they were last online, and how long you have played together. You can send messages to friends.
Requests: /friend add name | message sends a friend request with a short message. Incoming requests show up in the "Friends" tab together with their message; accept or decline them there.
Mailbox: messages from staff, raid reports, lottery wins, ticket replies, messages from friends and gifts land here. They are sorted into folders automatically (System, Friends, Support, Gifts). Pin important messages to the top (up to 20). Tick the boxes to select several messages and delete them at once; there are also "Mark all read" and "Delete read". Claim attachments (scrap, items) with a button.
Read receipt: for your messages to friends you see whether they were only delivered or already read.
Gifts: "Send gift" lets you send items to other players (up to 10 per day, claimable for 3 days) – with a personal note and a wrapping colour of your choice (red, gold, green, blue, purple, pink or silver).
Commands
/friend add Name/friend add Name | Nachricht/friend remove Name/mail