I think this can be simplified by simply allowing staff or the client to add additional addresses via CC, perhaps limit 5 maximum or something. If a ticket comes in via email and has users CC'd, include them automatically as CC's on the ticket. Staff and the client can add CC'd users via the web interface.

History Below
Feature request @ https://requests.blesta.com/topic/support-tickets-specify-ticket-contacts

When an admin replies to a ticket for a client, the primary client contact and other contacts may receive the ticket response.

This task will add a section on the ticket in the admin UI to specify the contacts that will receive ticket responses via email. How this looks in the UI should be considered, but I imagine we will need to know both the contact's name and their contact type. It may also be useful to know their email address since some contacts may have the same email address as the primary contact and there wouldn't be a need to send the email to both.

1. Update the admin UI to send an admin's ticket reply to a subset of the client contacts as defined on the ticket
   • When an admin replies by email, only ticket defined ticket recipients should receive an email notice about the ticket
   • When an admin replies by UI, the UI should allow the ticket contacts to be updated, and the email reply should be sent to the updated list (i.e. both occurring in the same request)

NOTE!

In addition to being able to select existing contacts to loop into this ticket, staff and the client should both be able to add email addresses as a "CC" in effect, to the ticket. The ticket system should accept an email reply from someone who was CC'd on the ticket, whether that is a contact that was assigned, or an email address added to the ticket.

The use case for allowing any email address to be added to a ticket, allows staff or the client to loop in another party who may be able to help with the issue at hand, but whom should not be a contact. For example, looping in someone from a data center to help diagnose an issue.