Inject Ticket ID into subject line of Inbox Replies

Since we don't have a customer facing inbox like Hubspot, our customers sometimes get lost what message relates to which ticket (when they have multiple issues in parallel). So it would be great if we could append the subject line of a message with ticket ID, so that the user can identify the messages related to a specific ticket in their inbox. This is possible in Zendesk.

HubSpot updates