The benefit of email is that no one owns it and that anyone can set up an email service with little effort. Email is very, very open, but the more vulnerable it is too and email is very open. Facebook is the number one sender of emails, churning out 1.8 billion emails a day. The trick is to inject trust back into email for consumers to make it more trustworthy again. With authentication, recipients can be confident that the sender was authorized to use the domain that appears in the field that appears to be in the domain.”]
Source: https://www.csoonline.com/article/3220434/the-incredible-success-and-utter-failure-of-email.html