Please help!!!! Error sending emails

Hello guys
We have a problem sending/receiving emails. Our main contact cannot send emails to our emails account(own domain). Here is what he get:


does "X-Symantec-TimeoutProtection: x" means that nicaraguense.ibw.com.ni (ISP's mail server) have installed symantec and have problems?

---------returned message begin----------------------------
X-Symantec-TimeoutProtection: 0
X-Symantec-TimeoutProtection: 1
X-Symantec-TimeoutProtection: 2
X-Symantec-TimeoutProtection: 3
Date: Wed, 7 Jul 2004 10:30:23 +0600 (GMT)
From: Mail Delivery Subsystem MAILER-DAEMON@nicaraguense.ibw.com.ni
To: cesesma@ibw.com.ni
Subject: Returned mail: see transcript for details
Auto-Submitted: auto-generated (failure)
X-Virus-Scanned: by amavisd-milter (http://www.amavis.org/)

The original message was received at Wed, 7 Jul 2004 10:30:20 +0600 (GMT) from pppmtgalpa8.ibw.com.ni [200.85.171.38]

----- The following addresses had permanent fatal errors ----- codeni@codeni.org.ni
(reason: 550 5.1.1 codeni@codeni.org.ni... User unknown)

----- Transcript of session follows ----- ... while talking to smarthost.ibw.com.ni.:
>>> DATA
<<< 550 5.1.1 codeni@codeni.org.ni... User unknown 550 5.1.1 <codeni@codeni.org.ni>... User unknown 503 5.0.0 Need RCPT (recipient)
Reporting-MTA: dns; nicaraguense.ibw.com.ni
Received-From-MTA: DNS; pppmtgalpa8.ibw.com.ni
Arrival-Date: Wed, 7 Jul 2004 10:30:20 +0600 (GMT)

Final-Recipient: RFC822; codeni@codeni.org.ni
Action: failed
Status: 5.1.1
Remote-MTA: DNS; smarthost.ibw.com.ni
Diagnostic-Code: SMTP; 550 5.1.1 <codeni@codeni.org.ni>... User unknown
Last-Attempt-Date: Wed, 7 Jul 2004 10:30:23 +0600 (GMT)
Return-Path: cesesma@ibw.com.ni
Received: from TECNICOS (pppmtgalpa8.ibw.com.ni 200.85.171.3
by nicaraguense.ibw.com.ni (8.12.11/8.12.9) with SMTP id i674UH5D000810
for codeni@codeni.org.ni; Wed, 7 Jul 2004 10:30:20 +0600 (GMT)
Message-Id: 3.0.5.32.20040707104257.00c35688@pop1.ibw.com.ni>
X-Sender: cesesma@pop1.ibw.com.ni
X-Mailer: QUALCOMM Windows Eudora Light Version 3.0.5 (32)
Date: Wed, 07 Jul 2004 10:42:57 -0500
To: "CODENI" codeni@codeni.org.ni
From: Cesesma cesesma@ibw.com.ni
Subject: Re: INVITACION
In-Reply-To: 000d01c46435$2baa93a0$0101a8c0@SERVIDOR
Mime-Version: 1.0
Content-Type: text/plain; charset="iso-8859-1"
---------returned message end-----------------

 

X-Symantec-TimeoutProtection: 0
Date: Wed, 7 Jul 2004 10:30:20 +0600 (GMT)
From: Mail Delivery Subsystem MAILER-DAEMON@nicaraguense.ibw.com.ni
To: cesesma@ibw.com.ni
Subject: Returned mail: see transcript for details
Auto-Submitted: auto-generated (failure)
X-Virus-Scanned: by amavisd-milter (http://www.amavis.org/)

The original message was received at Wed, 7 Jul 2004 10:30:19 +0600 (GMT) from pppmtgalpa8.ibw.com.ni 200.85.171.38

----- The following addresses had permanent fatal errors ----- comunsocial@codeni.org.ni
(reason: 550 5.1.1 comunsocial@codeni.org.ni... User unknown)

----- Transcript of session follows ----- ... while talking to smarthost.ibw.com.ni.:
>>> DATA
<<< 550 5.1.1 comunsocial@codeni.org.ni... User unknown 550 5.1.1 <comunsocial@codeni.org.ni>... User unknown 503 5.0.0 Need RCPT (recipient)
Reporting-MTA: dns; nicaraguense.ibw.com.ni
Received-From-MTA: DNS; pppmtgalpa8.ibw.com.ni
Arrival-Date: Wed, 7 Jul 2004 10:30:19 +0600 (GMT)

Final-Recipient: RFC822; comunsocial@codeni.org.ni
Action: failed
Status: 5.1.1
Remote-MTA: DNS; smarthost.ibw.com.ni
Diagnostic-Code: SMTP; 550 5.1.1 comunsocial@codeni.org.ni... User unknown
Last-Attempt-Date: Wed, 7 Jul 2004 10:30:20 +0600 (GMT)
Return-Path: <cesesma@ibw.com.ni>
Received: from TECNICOS pppmtgalpa8.ibw.com.ni 200.85.171.38]
by nicaraguense.ibw.com.ni 8.12.11/8.12.9 with SMTP id i674UH5B000810
for comunsocial@codeni.org.ni; Wed, 7 Jul 2004 10:30:19 +0600 (GMT)
Message-Id: 3.0.5.32.20040707104058.00c34e70@pop1.ibw.com.ni
X-Sender: cesesma@pop1.ibw.com.ni
X-Mailer: QUALCOMM Windows Eudora Light Version 3.0.5 (32)
Date: Wed, 07 Jul 2004 10:40:58 -0500
To: "CODENI" comunsocial@codeni.org.ni
From: Cesesma <cesesma@ibw.com.ni>
Subject: Re: =?Windows-1252?Q?Campa=F1a_?=
In-Reply-To: 002801c46434$8c0b6310$1401a8c0@comunsoc
Mime-Version: 1.0
Content-Type: text/plain; charset="iso-8859-1"