That's a nice writeup. Especially the mailing list part struck with me.

So which provider is it.

I've gone through a lot of providers in the last decade. Currently everything sits in the DC of my current employee, but I feel like a freeloader, which I am clearly am.

I work for a cloud provider, and even if I wanted to, I could not check for outgoing spam, other than reacting to the NOC mails.

Most mail server use transport encryption, which I can absolutly not inspect.

What does a provider make trustworthy for you?