Owning online real estate, not renting

There are many tools that a self-published author needs, and Mailerlite and Bookfunnel are two of them. Mailerlite runs the mailing list and Bookfunnel runs the eBook deliveries. I've used them both for the better part of ten years and have had zero complaints about them.
But it's still a case of paying rent on borrowed land. If Mailerlite or Bookfunnel decide at any time that I am violating some obscure policy, or they decide to close down, then I'm royally screwed as I will have lost my accounts.
That's why it's better to own than to rent. A few months back, not realising the full scale of what I was about to begin, I started building my own email subscriber list platform. Emails are now sent by Amazon AWS, and a platform on the site is run by Mail Pilot. Then, as if I wasn't masochistic enough, I also decided to go the whole hog and set up eBook delivery pages on the site as well. As you do. I must have been off my medication that day.
But ultimately, it's been worth it. I'm proud of what's been created. I'm saving around 60 Euros a month, not having to pay for Mailerlite and Bookfunnel. But cost aside, I also built these things with one thing in mind - absolute user privacy. Unlike Mailerlite and Bookfunnel, my setup has zero trackers.
We don't collect IP addresses, click rates, open rates, and no hidden pixels are hidden inside emails. Links are plain text with no long tracking codes attached to the end, so you'll always see where the link leads to before you click on it. Oh and there's a fallback plain text version of emails, if the user has disabled HTML emails.
With the lack of user data, segmenting user behaviour is extremely difficult. I have no way of knowing anything about the subscriber. All I know is that Joe with his email address has subscribed and confirmed he wants to be on my list. But after that, I know absolutely zero about Joe.
No exact location, no IP address, no click-through rate, no email open rates, absolutely zilch.
But the trade-off is worth it. These days, online privacy is something to emphasise as a sales pitch. People value it, and I know I do too.
The first emails went out last night without a hitch. But without Mailerlite, I now realise that I will be flooded by delivery failure requests (at their end, not mine), and auto-replies. Reading some of the auto-replies though is hilarious.