Agents and admins can choose receive email notifications of new tickets,  replies and other events.  This is particularly useful for low activity help desks where ticket volume is low.  To opt in to notifications, visit your agent profile by clicking on your avatar/image in the upper right of the admin panel.  There are several different types of notifications you can receive:

This will email you a notification any time a new private ticket has been received.  The notification will include the message from the user, and you can either click a link to view it online or reply directly to the email.

This will email you a notification any time a new public community topic is added.  The notification will include the message from the user, and you can either click a link to view it online or reply directly to the email.

This will email you a notification any time a reply to a private ticket has been received.  The notification will include the message from the user, and you can either click a link to view it online or reply directly to the email.  The behavior of this notification is slight different for agents and administrators:

    Administrators: admins will receive an email notification for every customer reply received, whether or not the admin is assigned to that ticket, and     regardless of the tickets group affiliation.

    Agents: agents will receive an email notification for customer replies to tickets the agent is assigned to.

This will send you an email alerting you that you have been assigned to a ticket. 

This will email you a notification if and when you are @mentioned in a ticket.  @mentioning also makes the person you mentioned a follower of that ticket.

This will email a notification whenever a customer replies to a ticket you are following.

Web notifications:

You will also see notifications appear in your web browser and admin panel.  These notifications cannot be controlled with the preferences above.