We've appended - {{ticket.subject}} #{{ticket.id}}] to the subject of every email sent through the system. Everything appears to thread properly EXCEPT:
When an agent replies to an email with the subject:
New Reply Received - {{ticket.subject}} #{{ticket.id}}]
From Email Notifications: Agent Notification / Requester Replies to Ticket)
This appears to be the only instance that the threading fails. Suggestions?