When you email a file to yourself and open the attachment to work on, you must save the attachment to your system first (i.e. My Documents or desktop). When you download your attachment, do not choose “Open”; choose “Save”. Then open the saved file from the location in which you saved it (My Documents, for example).
If you choose “Open” to work on your files, you will lose your progress, even if you save as you work. This is not reversible. We cannot recover your lost progress. When you open an attachment from your email, you are only working from a temporary file that is deleted when you close the program in which you are working. When you save the attachment instead, you are creating a file that is stored permanently.
Please keep this simple step in mind as you work on important projects and papers.
More information is available from an external site, Ask Leo.