I am using a small German email provider and I can't remember the last time I got spam. What's even crazier is that they are so confident in their spam filter

I am using a small German email provider and I can't remember the last time I got spam. What's even crazier is that they are so confident in their spam filter that they simply reject mails classified as spam. But that hasn't been a problem since the few years I have been using them as well.