clean sender domains/IPs are marked as Spam heurictically; hits=50, tests=ipchecker:xxxyyy
same issue as already mentioned under tag from email.security.cloud on July 17th 2017 with techn.support engineer Sym_Jan_T, but thread locked there with no real answer.
We do have the same issue.
Different test show up that some mail provider do mark as spam, some don't with spam-level 0