mail headers question

From: al (al_at_somplace.com)
Date: 04/22/04 

Date: Thu, 22 Apr 2004 19:59:01 GMT

Here's a sample spam headers that I received today.
There are three domain addresses here:
counsellor.com, fia74-110.dsl.hccnet.nl and iwexx.japan.com
My question is, which address do I need to block so that I don't receive
spam from this source again.

Return-Path: <tfzqzxa@counsellor.com>
Received: from fia74-110.dsl.hccnet.nl (fia74-110.dsl.hccnet.nl
[62.251.110.74])
 by mydomain.com (8.12.8/8.12.8) with SMTP id i3KD8X56523724
 for <al@mydomain.com>; Tue, 20 Apr 2004 06:08:35 -0700
Received: from iwexx.japan.com [72.224.120.76] by 62.251.110.74 with wbttrf

thanks,
al