That’s really odd that it said it was automatically going to your Gmail. That has to actually be turned on in the settings, and I believe it’s a secondary backup. There’s four save locations you can pick from. They are Google Drive, Dropbox, OneDrive or make a Local Backup on the actual device. I’m betting what might’ve happened is you didn’t choose one of those options for the backup location, so it didn’t actually save the backup at all there wasn’t anything to send to your Gmail. Just make sure if you do try the app, go into the settings and pick a save location before you run any backups.