Return-Path: <foo@mail.com>
From: Foo <foo@mail.com>
To: some_group@bar.com, alice@foo.com
Cc: bob@FOO.com, carol@example.com
Date: Fri, 15 Jan 2016 00:12:43 +0100
Message-ID: <51@foo.bar.mail>
Mime-Version: 1.0
Content-Type: text/plain
Content-Transfer-Encoding: 7bit

Email from a domain on blocklist or allowlist.