It would be great if there was a way to drag and drop an open PDF on to an email that is already open. The "Attach to email" feature only opens a new email. For example, I'm in an email chain where I'm periodically downloading PDFs from a software, and I want to attach it to the email chain and send it off. Currently, I need to save the document locally and then attach it, which takes extra time and space. It would be helpful if there was a way to just drag and drop the PDF onto the open email.