You can type /ch afk [Afk Message] And everytime someone messages you you wil automaticaly reply
<AFK> [Afk Message]! It is very useful when you get a lot of PM's and you are going to be afk for something like dinner! To turn this off just simply do /ch afk again! Or you can do it to automatically respond to PM's if you are building or some other activity that requires your full activity.​