Is that the "Just So" story that people who don't work with email at scale believe? Email deliverability is a full time job. There are so many "potential spam"

Is that the "Just So" story that people who don't work with email at scale believe? Email deliverability is a full time job. There are so many "potential spam" markers that are interpreted differently (and opaquely) by different ESPs. Getting your email delivered to a lot of people is essentially non deterministic. Including a link to a Google Doc in your message body is enough to get you blacklisted by some email providers if you don't have a prior history with them. Yes, there will usually be some process to get off the blacklists and doing it will mostly stick even if you continue to email Google Docs to people. But the key word there is mostly. As I said, deliverability (at least at scale) is a full time job.