Date: Mon, 10 Jan 2011 12:00:00 -0500
From: from@example.com
From: evil@example.com
Sender: send1@example.com
Sender: send2@example.com
To: to@example.com
Date: Tue, 12 Jan 2011 12:00:00 -0500
Subject: An email
Subject: Dup subject
Message-ID: <11111111-bdfd-ca83-6479-3427940164a8@invalid>
Message-ID: <22222222-bdfd-ca83-6479-3427940164a8@invalid>
References: <aaaaaaaa-3d7b-22d2-f859-4c1e6a2164d6@invalid> <bbbbbbb-3d7b-22d2-f859-4c1e6a2164d6@invalid>
References: <ccccccc-3d7b-22d2-f859-4c1e6a2164d6@invalid>
Content-Type: text/plain

Hello there