How to use @mentions in comments
Mention one teammate
You can mention someone using the @ symbol within the comments section of a conversation, and this person will receive an email notification and/or an in-app notification, depending on his or her notification settings.
Mention a non-teammate
You can mention someone who does not share a team with you. Those users will be marked with the “(not in team)” text in the autosuggest menu.
Mention your whole team
You can mention everyone on your team using @all, and every teammate will receive this mention in their inbox and/or as a notification.
Mention a custom group
You can also create an @mention shortcut that will mention a specific group of people, using rules. For instance, this rule will allow you to use the mention @cx to notify the teammates listed below.