General

The Message window allows you to chat privately with friends and other eMule users. The difference to the IRC window is, that you will connect directly to the other client without using any server. There are no "rooms" or anything but just you and your chat partner.

Details

The Friends list (1) contains all your eMule friends. The easiest way to add a friend is using the context menu in one of the lists of the Transfers window and clicking on the "Add to friends" option. For example if some user is downloading the same files as you are, you might want to chat with him about it or see which other files he is also downloading. Another method is adding a friend directly by right clicking on the Friends list and using the "Add..." option. You will then have to provide his IP and TCP port, so eMule knows how to reach him.
You can find more details on what the colors of your friends mean and what possibilities your have in this topic.

To write and read messages in a chatsession use the Messages panel (2). This is quite self-explanatory, just start a chat session (for example with a friend in your Friends list), type in the message and click on "Send".
If you start a chat session with a stranger, you might be asked to solve a Captcha (an image which shows letters you have to type in) first. This is a spam protection of eMule to avoid unwanted automated messages.