Delivery Failure through Outlook 2003

[msilverman]

Hi all,

We are having some trouble with Outlook on a particular computer in our office and hoping someone can shed some light on the issue. Recently, emails have been bouncing back to a particular user in our office when he sends email to another user within our company domain name, or when he copies himself on an email to a client with a different domain name.

The following is the error message he receives when replying to a domain (in this case, Yahoo) and CCing himself on the email. I have inserted "email" and "domain" to signify our user, and "recipient" to signify the client. I have bolded what I assume is the underlying error message.

Please note, this only happens when sending mail from the user's Outlook program, and NOT when he sends mail from our webmail client. This has led me to assume that it is an issue with Outlook, and not with our server or hosting company.

------

-----Original Message-----

From: System Administrator [mailto:System Administrator]

Sent: Tuesday, July 17, 2007 12:00 PM

To: email@domain.com

Subject: Delivery Failure

Could not deliver message to the following recipient(s):

Failed Recipient: 'email@domain.com'

Reason: Remote host said: 504 <'email@domain.com'>: Recipient address

rejected: need fully-qualified address

-- The header and top 20 lines of the message follows --

Received: from w149.z065106186.nyc-ny.dsl.cnc.net [65.106.186.149] by

mail32.safesecureweb.com with SMTP;

Tue, 17 Jul 2007 11:59:18 -0400

Reply-To: <email@domain.com>

From: "Sender" <email@domain.com>

To: "recipient" <recipient@yahoo.com>

Cc: <'email@domain.com'>

Subject: RE: [sUBJECT]

Date: Tue, 17 Jul 2007 11:58:55 -0400

Organization: [ORGANIZATION]

MIME-Version: 1.0

Content-Type: multipart/alternative;

boundary="----=_NextPart_000_0032_01C7C869.DA174D70"

X-Mailer: Microsoft Office Outlook, Build 11.0.5510

X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3138

In-Reply-To: <310338.80379.qm@web30506.mail.mud.yahoo.com>

Thread-Index: AcfId7I3XtqLwWJyQZGjG/iXoUD8PgAE0rww

This is a multi-part message in MIME format.

------=_NextPart_000_0032_01C7C869.DA174D70

Content-Type: text/plain;

charset="US-ASCII"

Content-Transfer-Encoding: 7bit

[MESSAGE TEXT]

--------

I am considering backing up the .PST file and re-installing Outlook from scratch on this computer, but before I do, I was hoping to grab a suggestion or two on what might be causing this issue, and if it is fixable without going through that headache. I havn't been able to find any relevant info on the web or on Microsoft's knowledge base. I beleive we are running Outlook/Office 2003 on that machine.

Thanks in advance for any advice.

-Matt