Why are the email providers so bad about this? When I check my "spam" filder in Gmail, around half the email is not spam. Is it because humans are so bad at classifying spam?
This is an honest question, in my opinion the only way to make Google more friendly with self-hosted mail servers is their users complaining about or leaving Gmail.
google has one of the worst spam filters. It can be done much better, and google could do it much better.
But I suppose they are just big enough now. Can't reach your contacts that use google? Well, just sign up to google as well, then you can reach them.
People like you are the reason google can behave like that.
