Messages being rejected Exchange 2010

Just started receiving the following message from one sending address so far:

Checked for open relay and blacklist status.  All good there.  Could something have changed on the receiving side?

Diagnostic information for administrators:
Generating server:

Postini #554 No relaying allowed - psmtp ##
Original message headers:
Received: from ([::1]) by ([::1])
 with mapi id 14.01.0218.012; Mon, 23 Sep 2013 13:23:13 -0500
Subject: RE:
Thread-Index: Ac64iKvupebToFIPQQWakIkeQ5M8tAAAT+Iw
Date: Mon, 23 Sep 2013 18:23:12 +0000
Message-ID: <>
References: <>
In-Reply-To: <>
Accept-Language: en-US
Content-Language: en-US
X-MS-Has-Attach: yes
x-originating-ip: []
x-tm-as-product-ver: SMEX-
x-tm-as-result: No--56.984100-5.000000-31
x-tm-as-user-approved-sender: No
x-tm-as-user-blocked-sender: No
Content-Type: multipart/related;
MIME-Version: 1.0
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Adam FarageSr. Enterprise ArchitectCommented:
Are you using postini, or is the recipient using postini?

I know postini requires (or has the option to require) all users to be added to the box, so make sure the user is allowed to send through Exchange to the Postini relay. That is an issue I see a lot with new / larger Postini deployments.
WebccAuthor Commented:
Correct, that is what we are receiving from the recipient.  We are using Exchange.

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