If the reply is from the requester of the ticket or anyone part of the ticket conversation thread(in cc to the ticket conversation, added as an approval, if the ticket was forwarded to them), Freshservice will check for the Message-ID and ticket ID in the subject line and append the reply to the original ticket accordingly.
The system will look to append the reply based on the Ticket ID in the subject line, which would have to be of the format [#{{ticket.id}}](for ex., [#INC-12345], where the ticket id is INC-12345). This concept is used for replies to emails sent by Automations or Email Notifications
