There may be times when you want to send a message to your server users that they all can see when they log in. While “wall” allows you to send messages to currently logged in users, you need a different tool to make sure all users get it whenever they happen to log in. MOTD (message of the day) can serve that purpose. You can also use it just to display general reminders.
The easiest way to change the motd is to edit the /etc/motd file. You can place any information you want in this file. It could be a warning about unauthorized access, contact information for the administrator, helpful tips for new users, or even just general information about the server.
Keep in mind that anything you put in the motd will be sent to all users on your system every time they login. Make sure it is something useful and not annoying. There are also programs you can use that give random quotes for the message of the day if you would prefer that.
Example message of the day:
Welcome to Server 78923, Alpha Data Center
All activity on this server is monitored. Any unauthorized use of this server and its user accounts is prohibited.