Nope. Take for example Gmx.

Due to the heuristics some of the providers have, such as Microsoft, they will start classifying mail sent from gmx as spam and auto move it to people's spam folder. They have developed their own internal trust metrics and these periodically just spambin low trust servers

My mail provider isn't that big. We got blocked by both outlook and gmail, but I duckduckwent a workaround which worked. Something about editing some mail record somewhere. Can't remember what, I'm afraid.