From WHMCS Documentation
Support ticket actions trigger email notifications as shown below:
|Action||Ticket Watchers||Department Members*||Flagged Admin||Owner||Users||Contacts||CC Recipients|
|Change of Ticket Options|
|Change of Ticket Department|
You will not receive an email notification for any changes you initiate yourself. Notifications may also depend on permissions and the origin of the ticket.
* Department Members only receive Client Reply and Change of Ticket Department notifications when there is no flagged admin user.
- Ticket Watchers — Any admin user who is watching a ticket via the Admin Area.
- Department Members — Any admin user who chose to receive ticket notifications for a given Support Ticket department and has the Support Emails Admin role.
- Assigned User — Any admin user to is assigned to or unassigned from a ticket.
- Owner — The related client's account owner.
- User — A user with access to the related client.
- Contact — The related client's contacts.
- CC Recipients — A recipient who has been added to the ticket to receive a carbon copy (CC) of ticket-related emails.