Comment 54 for bug 490935

Yes, this is a no-brainer. Once a message i recived it is in the hands of the reciever to do what he likes with, including changeing the subject or any other part of the message.

If the sender wants to make sure that his words are not tampered with he should digitally sign his message. This is the only way for him to be sure of this there are many other ways to change this, they may just be a little more inconvienint. In fact, if it becomes commonly known that mail can be changed, peple would be more careful, and start using cryptography and/or digital signature for important messages.

There are far too many people that send mail with bad subjects, not to have this feature. Besides, the title may be perfectly good on the sender side, but totally insufficient on the reciever end. E.g a customer may send "Regarding my order" but to sombody that handles thosands of orders that may not be sufficient.