Shopify Contact form SUBJECT LINE text : How to change?

It’s very difficult when looking through my inbox and every subject line is the same to remember which email I wanted to address or which one I had just looked at. Also some email clients will lump multiple customer’s conversations into the same thread because of the subject line.

I just want the customer to input a subject line. Because they can’t, I will have to remove all contact forms from our website and just put our email address for them to copy and paste.