SupportCandy Agentgroup Addon GPL Overview:

As the name suggests, you can create groups of agents to whom you can assign tickets just like individual agents.

Every agent in the group can manage tickets assigned to the group. If you want to assign the ticket to the group and expect any available agent in the group to pick the ticket, this add-on is for you.

An email notification with the recipient “Assigned Agent” is enabled, for ticket assigned to agent-group will get sent to all agents of the group.