How to disable no subject warning is Mac Mail?

This is quite disturbing that I think an email is sent only to come back hours later and discover that the message has not been sent because there is this prompt that tells me there's no subject do I really want to send this. Is there any way of turning off this to allow me to just always send email without a subject. I don't need a subject line and I don't need to be told that I need a subject line I just want to send an email.

"This message has no subject. Are you sure you want to send it?"