I'm guessing substack is a high volume email sender, do you guys use an API or in-house tech for that? Any interesting stories about keeping your mail out of spam filters/your IPs off blacklists/Nigerian princes from starting newsletters?
I don't want to get too deep into the details here other than to say at a product level we're focused on being respectful with the access we get to people's inboxes. We hate junk mail as much as everybody else, and being good citizens is necessary (but not sufficient) to deliver lots of email.
