Earlier quoted context omitted.
Well, deliverability and being self-hosted might not go well together these days. There is a LOT you need to go in terms of setting up the relevant infrastructure; the newsletter software is just a tiny fragment of it. And even if your carefully crafted infrastructure works now, it can suddenly stop, just because some big e-mail hosting service decides they implement a major change (see e.g.: http://tanguy.ortolo.eu/…
See, I get your point, but my experience is different. All the transactional emails of my SaaS are sent out with PHP's mail() which is obviously the worst infrastructure setup you can get and only a fraction is marked as spam for my receivers. Same is true for my contact form. A copy is sent to the receiver. This works with my providers SMTP server and again, not that many problems with deliverability. In my limited…
That's where the whole deliver ability lark comes in, and is why we offload non-transactional emails to the likes of bronto and adestra. One less thing to worry about.