mail plugin

I saw the default installation refers to some MailPlugin..... com.xpn.xwiki.plugin.mail.MailPlugin A google on this only revealed a bunch of checkins. How do I use this Mail Plugin? I am assuming it is to register for notifications on pages? I saw another plugin that I would have to install(and frankly, I tried but the instructions refer to stuff that isn't there or I can't find in xwiki like Xwiki.Toolbar page). Any info on mail plugins would be appreciated. thanks, dean