Saving to the Cloud

I’ve been using Gmail to back up my book. I upload my notes, outline and current draft after every session of work. Then I put a Gmail label on every one of the emails, so they stand out. I do send the files to an alternate email as well, so I’m sure I have them sufficiently backed up.
This weekend I cleaned out my inbox (long, long overdue), until there was little left except for the record of my endeavor so far. I’m more than halfway through the book, and there are 26 emails. That’s 26 sessions of writing, ranging from one hour to six hours each time. The unintended side effect of using email to back up my work is that I now have an exact chronology of my effort.