Mention a person in a message on Mac
With macOS 11 or later, you can mention other people in a conversation to call their attention to a specific message. Depending on their settings, they’re notified even if they turned on Hide Alerts for the conversation.
Note: To send mentions, you need to use iMessage.
Mention a person in a conversation
In the Messages app on your Mac, select a conversation.
In the field at the bottom of the window, begin typing the name of a contact you want to mention.
After you type the person’s name, it becomes dim — click it, then select the contact’s name when it appears.
Tip: You can also mention a contact in Messages by typing @ followed by the contact’s name.
Set notifications for mentions
You can receive a notification whenever anyone mentions you, or only when certain people mention you.
In the Messages app on your Mac, choose Messages > Settings, click General, then select (or deselect) “Notify me when my name is mentioned”.
When this option is unselected, you get a notification only if you’re mentioned by someone who’s in your contacts or is someone you previously received messages from.