You can send a Message of the Day to all active session users and to new users when they log into the vSphere Client.
The Message of the day text is sent as a notice message to all active session users and to new users when they log in.
- On the Home page of a vSphere Client connected to a vCenter Server system, click the Sessions button.
- Type a message in the Message of the day field.
- Click Change.
The message is broadcast to all users logged into the vSphere Client.