“(…) I use Wp-db-backup plugin for scheduling the database backup. There is a feature in that plugin that allows you to send the scheduled backup to your mentioned email address as attachment. (…)

Storing your database backup in Dropbox will assure you about the availability of your important data as it will synchronize that files automatically to your computer. (…)

All the workaround is to arrange your Dropbox such that you can upload the email attachments to your Dropbox automatically. Send to Dropbox is a great application that allows you reach the above goal. So, go to “Send to Dropbox” and allow the access to your Dropbox account. (…)”

via Schedule WordPress Database Backup to Dropbox Account.