Exceeding Max Emails per hour - Spam suspected

We are getting the following error

Domain xxxxxxxxx.co.id has exceeded the max emails per hour (250/200 (125%)) allowed. Message discarded.

------ This is a copy of the message, including all the headers. ------

Return-path: <xxxxxxxxxxxxx.co.id>
Received: from [180.243.95.123] (port=22185 helo=[192.168.0.110])
by orange.nusantaraserver.com with esmtpa (Exim 4.80)
(envelope-from <xxxxxxxxxx@xxxxxx.co.id>)
id 1U9ouj-003T5F-Ex
for xxxxxxx@yahoo.com; Mon, 25 Feb 2013 10:39:42 +0700
From: Andrew Derrick <xxxxxx@xxxxxxxx.co.id>
Content-Type: multipart/alternative; boundary="Apple-Mail=_CF6F8A1B-2A7A-4810-B1D6-2F4982C1F2B7"
Subject: Test Yahoo 2
Date: Mon, 25 Feb 2013 10:39:35 +0700
Message-Id: <45A2B9BE-CEF0-40F8-83CE-39BB6521F2E9@xxxxxxx.co.id>
To: xxxxxx@yahoo.com
Mime-Version: 1.0 (Apple Message framework v1283)
X-Mailer: Apple Mail (2.1283)


--Apple-Mail=_CF6F8A1B-2A7A-4810-B1D6-2F4982C1F2B7
Content-Transfer-Encoding: quoted-printable
Content-Type: text/plain;
charset=us-ascii


Any guidance or assistance is appreciated..

Andrew