change subject for the message on fly while sending it

Hello there

In service there is only one subject you can modify if needed and all messages will be sended by using this subject. However, some times if you want to discuss with third party and send out message with different subject, it is not possible without changeing ticket title and after sending it, change it back as it was. Is it possible to show also subject for every message and also changeing it before sending message? 

Thanks

Regards

Ingar