It works, somewhat.

With "gmail.com" (very popular email provider), the "block_list" property in "meta" property is set to "false". That means that the domain is not blocked as used for disposable addresses.

With "gufum.com" (domain used for disposable email addresses), the "block_list" property in "meta" property is set to "true". That means that the domain is blocked as used for disposable addresses.

But why with both "svrjs.org" (my web server's domain; its MX records points to Zoho Mail) and "interia.pl" (a Polish email provider) have the "block_list" property in "meta" property set to "true", meaning they are blocked as used for disposable addresses, even though it they probably are not?