I received an e-mail from

I received an e-mail in Outlook Inbox from USPS Service <status_item@usps.com> with the attachment Label_Parcel_USPS_13-114.zip

However, the ip address in the e-mail message header is

How can I find out "who is" or "what is" using on our network?

Thanks for your help.
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LessonsLearnedAuthor Commented:
The header information is:

Received: from outlet-web.jp ( by SD1.sd.local (
 with Microsoft SMTP Server id; Mon, 9 Apr 2012 12:39:03 -0700
Received: by outlet-web.jp (Postfix, from userid 2)      id DE98084436D; Tue, 10
 Apr 2012 04:38:17 +0900 (JST)
To: <jim@mmpph.com>
Subject: Postal notification
From: USPS Service <status_item@usps.com>
X-Mailer: mPOPWeb-Mail2.19
Reply-To: USPS Service <status_item@usps.com>
MIME-Version: 1.0
Content-Type: multipart/mixed; boundary="----------13340002974F833AA9C4324"
Message-ID: <20120409193817.DE98084436D@outlet-web.jp>
Date: Tue, 10 Apr 2012 04:38:17 +0900
Return-Path: daemon@outlet-web.jp
X-MS-Exchange-Organization-AuthSource: SD1.sd.local
X-MS-Exchange-Organization-AuthAs: Anonymous
LessonsLearnedAuthor Commented:
Network Solutions Whois states equates to outlet-web.jp

Domain Information:
[Domain Name]                   OUTLET-WEB.JP

[Registrant]                    STB,Inc.

[Name Server]                   01.dnsv.jp
[Name Server]                   02.dnsv.jp
[Signing Key]                  

[Created on]                    2007/06/04
[Expires on]                    2012/06/30
[Status]                        Active
[Last Updated]                  2011/07/01 01:05:05 (JST)

Contact Information:
[Name]                          STB,Inc.
[Email]                         kobayashi@stb-libman.jp
[Web Page]                      
[Postal code]                   441-8113
[Postal Address]                Toyohashi-shi
                                333 Nishimiyuki-cho Aza Hamaike
                                Sience Core 109
[Phone]                         0532-38-6595
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tobywestonConnect With a Mentor Commented:
This is not an internal IP, it will be coming externally from one of the many spam bots around the world.

Doing an IP lookup will show you roughly where.
Dave BaldwinConnect With a Mentor Fixer of ProblemsCommented:
The first "Received:" line tells you who it came from.  It is just spam.  They faked all the other email addresses.
LessonsLearnedAuthor Commented:
Thank you very much.  When I pinged, I got 4 replies.  I thought that because the IP address began with 192, that it was a computer or device located in my office, but "tobyweston" said it was not an internal IP.
tobyweston is correct.  Here are the private IP address ranges:

IANA-reserved private IPv4 network ranges Start End No. of addresses
24-bit block (/8 prefix, 1 × A) 16777216
20-bit block (/12 prefix, 16 × B) 1048576
16-bit block (/16 prefix, 256 × C) 65536
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