[baobabKoodaa]

> Its true, that I did not refer to deliverability. But I can do this now :) Mailinabox has a dahboard that shows you if you are on any spam list. It will also just stop with the setup, if it detects, that the IP of your machine is blacklisted.

I have never been on a spam list. My IPs have never been on a blacklist. And yet, my mail was often delivered to spam folder (as opposed to inbox) on Outlook and Gmail.

> The cases where my email got blocked, I always received an email back from the box, so I think there are no cases where my email just disappeared into the dark.

In the vast majority of the cases where your email is not delivered to the inbox of the recipient, you will not get any notification. In these cases your mail will usually be silently placed into the spam folder, and sometimes it will be blackholed completely (not even landing in the spam folder).