No, that was pretty much how email worked for a long time. And IRC.

I remember someone even making a song “I am going to ban your domain” to the tune of “they’re coming to take me away” to mock sysadmins who took this drastic measure too quickly.

Some university servers would block all email from abroad except for some whitelisted servers. My school blocked emails from another school because the students were badly policed and would just harrass other schools.

Some domains were universally blockdd because they were used by spammers and scammers.

This mostly softened into spam folders and increasingly sophisticated filtering, which is dominating today.