>Well, it's not a big deal. If you think it's not consistent with the rest of application, then the Cancel button is not important. I can use Back button.
>
>There probably should be a check on this form, saying "Don't send message content" (or something similar). It would be unchecked by default. So, if I don't want to send a message content, I'll check this checkbox.

It only sends if a text is present. Otherwise, it's the same as it used to be.