This plugin activates the maintenance mode for your server.
The command to activate it is /maintenance <enable or disable> and you need the permission "maintenance.command" or if you are op on the server.
When I run the command it will remove all those who do not have the "maintenance.permission" permission or if they are not ops.
In the config.yml file you can configure whether a custom motd comes out when it is in maintenance mode and you can customize it. You can also modify the message that people get when they try to enter maintenance mode.