bmail is a personal mail tool that runs on its owner's own computer. It connects to one Gmail account through the Gmail API, stores the mail in a local database, sorts it by kind (marketing, notification, transactional, financial, personal, recruiting, one-time codes), extracts orders, shipments, trips and subscriptions from it, and helps the owner unsubscribe from bulk senders and archive by kind.
It is not a hosted service. There are no accounts, no servers run by anyone other than the owner, and no data from anyone but the owner. Each person who runs bmail creates their own Google OAuth client in their own Google Cloud project and connects their own account to it.