The welcome message in Rich Message Announcer is made to only display to the player who enters the server. I should have made it clearer in the plugin description, sorry.
What you are looking for is a Join / Leave messages plugin which will announce in chat whenever someone enters or disconnects from the server. The following plugins have this feature:
If you want to also add /stats command to your server, I recommend using the Player Stats as it can also display the rank of the player who joins the server.
If you need a simple plugin which only displays who joined or disconnected use the JoinLeaveMessages.
