How to prevent mac from displaying short messages?

1. Click the Preferences option in the information menu at the top of the desktop.

2. Then click the "Account" column at the top of the settings window.

3. Then select your iMessage account in the left pane and click the "Block" tab on the right.

4. Then, you can see the blocked numbers in the list. Click the "+-"sign in the interface to add or delete blocked numbers.