It is notoriously impossible to host your own email. Large email providers have created an oligopoly of email "quality" acceptance, and there's effectively no

It is notoriously impossible to host your own email. Large email providers have created an oligopoly of email "quality" acceptance, and there's effectively no way to get your deliverability to a reasonable rate unless you use one of them. I don't think it's necessarily malicious in nature - more the product of spam filtering. I wonder if email authentication methods like DKIM/SPF/etc.. help this problem these days.