Please correct me if I am wrong, When the external email address receives an email notification you want to show the ticket number in the subject of that email?
I used the email notifications to add the [#{{ticket.id}}] to the ticket.
I want the C00061272 ticket number taken from the ticket reply and added to the ticket subject, so when the email goes back to their system it doesn’t create a duplicate ticket.
@max.danter If I understood the ask correctly, while you forward a ticket, the ticket_id is kept in the hidden field of the email and it is being used by helpdesk to add the email reply as private note in your ticket.
If the original email body is intact as is in the email reply, it should not create a duplicate ticket.
We have an api: Service Desk API for Developers | Freshservice which can update the subject of the ticket. But please make sure the ticket Id in the response is added as part of body of the reply, since we will be not be able to access the subject part of the reply