Mail Returned with Host not Found error

[Nilesh <niluforalways yahoo com>]

Hello All,

My Friend sent mail me on my company address but it
bounced back to my friend. my Id is existed in my
company server can someone tell me why this error.
please check this error
thanks
-----Original Message-----
From: Mail Delivery Subsystem
[mailto:MAILER-DAEMON ext-ch1gw-1 online-age net]
Sent: Friday, January 30, 2004 11:07 AM
To: Bulkes, Cherik (MED)
Subject: Returned mail: see transcript for details


The original message was received at Fri, 30 Jan 2004
12:07:11 -0500 (EST)
from int-ch1gw-6 [3.159.232.70]

   ----- The following addresses had permanent fatal
errors -----
<nilesh extenprise net>

   ----- Transcript of session follows -----
550 5.1.2 <nilesh extenprise net>... Host unknown
(Name server:
dns.extenprise.net.: host not found)



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