Windows 7 Gmail will not backup

Using Comodo many years, now Intewrnet Premium free. Now have Windows 7 desktop. Used to use Backupify free to backup emails, but service now withdrawn. Installed Comodo Backup free today. Want only to backup emails. That takes me to Windows Mail and Windows Livemail. Tick both and away we go. After variously 2, 4, or 9 minutes Program stops saying no content.
So questions - does CB backup Gmails - if so, why do I have this problem? - I note some years ago CB had issues with Windows7, but I assume these sorted?

Many thanks.