Constant Content

I got contacted by a client via private message about some content he purchased wanting me to give him a little chart to go along with it. He seems to think that I can send him a doc attachment in my reply using the CC message system, but there is no attachment button that I can see. He was able to send an attachment to me of a screen shot showing how to send attachments, but the button he shows in the screenshot doesn't exist on my end. Is it possible for writers to attach things in the message system?

I don't think it's possible for writers but it is possible for customers. You can try emailing support. Sometimes they act as a liason and will forward documents back and forth. You might be able to submit it like an article with a note to the editors explaining.