I generally consider "emails to existing customers" to be [bacn](https://www.bbc.com/news/technology-21830739 https://www.bbc.com/news/technology-21830739), in

I generally consider "emails to existing customers" to be [bacn](https://www.bbc.com/news/technology-21830739 https://www.bbc.com/news/technology-21830739), in that they're neither ham nor spam.