Incomplete e-mail on my desktop was transferred to my iPhone and is no longer on my desktop. I had not completed the e-mail and intended to attach two attachments. How do I move it back to the desktop from my iPhone?

I am using a new 27" iMac Intel and I have a 5s iPhone. I am using iPhone iOS 8.3 and OS 10.10.3. I was typing an e-mail on my desktop when I turned on my iPhone, i.e., pressed the "home" button. The incomplete e-mail from my desktop immediately appeared on my iPhone and is no longer on my desktop. I need the e-mail on my desktop computer to affix two attachments to it and save to a special folder on my desktop. How do I move the e-mail from my iPhone back to my Desktop so that I can affix the attachments to the e-mail, send from my desktop, and save it in a special folder where I need to keep it? Bewildered and clueless in Atlanta.