In-Game Chat

Messenger

Press the hotkey E on your keyboard to open/close your Messenger Window. This in-game messenger can be used just like your typical instant messenger program. You can add or delete friends, block messages from certain characters, send messages to friends who are online or offline, and organize your messages for your party mates or guild mates. To send messages to a friend who is offline, right-click on the character's name, click on "Send Message", the Message Window appears, then type your message in the field and click on "Send". If you click the Memo button at the bottom of the Messenger Window, you can view the messages sent to you.

Add friend - Left click on this icon and a prompt will appear. Enter the name of the friend you want to add. (The other player has to accept or he/she wont show in your messenger)
Search friend - Not yet implemented.
Check offline message - This icon will let you check messages that were sent to you while your character is offline.
       
Another way to add someone to your messenger is:

Open the character menu : Press the Alt key on your keyboard, then click on
the character you want to add. Choose add messenger, you will now send a message to the other player to ask if he/she wants to be your friend. (The other player has to accept or he/she wont show in your messenger) Others may add you in his/her friend's list, simply click the Yes button on the confirmation window to complete the registration.

Status

Click the arrow to open your characters status window.
You can set the status of your character for your friends to see.
If your online, offline, eating, vending etc.
When you are leveling put it on Addict Mode so you don't get disturbed.

AFK  - Means Away From Keyboard.

Chat Box

This is where you can view and type messages or "Chat". Just press the Enter key to
toggle the chat mode on, type your message, and press the Enter key again to send.

Chat Macro

Macro saves you time from chatting. Just type in your commonly used
sentences and drag the Macro icon either in the hot keys or quick slots.
 
Now you only have to push the hotkey you dragged the icon too,
or click the icon with your mouse in the quick slot.