Automatic Mute of all channels but some specific

I've recently been having a struggle with the fact that if I want to mute all channels (mentions, etc) except one I have to do it manually. Please add this as it is a struggle to do this if someone is dealing with a mega server.  Someone noted in one comment of another topic to do with this something to do with overriding the server notifications on a specific channel, but however when I mute the server and try to override a certain channel the only option available is mute.