LinuxQuestions.org - local postfix server not able to send mails to other domain

hi all,

i have configured local postfix server.we are able to send and receive mails locally but not able to send or receive mails from other domain.

please help to configure postfix to send and receive mails from other domain.

please send me in dtail to configure

From: Mail Delivery Subsystem <MAILER-DAEMON@test4.cw.com>
To: <root@test4.cw.com>
Subject: Returned mail: see transcript for details
Auto-Submitted: auto-generated (failure)

[-- Attachment #1 --]
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The original message was received at Fri, 13 Mar 2009 14:51:09 +0530
from localhost [127.0.0.1] (may be forged)

----- The following addresses had permanent fatal errors -----
<subramanya@chipwerks.com>
(reason: 550-Verification failed for <root@test4.cw.com>)

----- Transcript of session follows -----
... while talking to chipwerks.com.:
>>> DATA
<<< 550-Verification failed for <root@test4.cw.com>
<<< 550-The mail server could not deliver mail to root@test4.cw.com. The
+account or domain may not exist, they may be blacklisted, or missing the proper+dns entries.
<<< 550 Sender verify failed
550 5.1.1 <subramanya@chipwerks.com>... User unknown
<<< 503-All RCPT commands were rejected with this error:
<<< 503-Sender verify failed
<<< 503 Valid RCPT command must precede DATA

[-- Attachment #2 --]
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Reporting-MTA: dns; test4.cw.com
Received-From-MTA: DNS; localhost
Arrival-Date: Fri, 13 Mar 2009 14:51:09 +0530

Final-Recipient: RFC822; subramanya@chipwerks.com
Action: failed
Status: 5.1.1
Remote-MTA: DNS; chipwerks.com
Diagnostic-Code: SMTP; 550-Verification failed for <root@test4.cw.com>
Last-Attempt-Date: Fri, 13 Mar 2009 14:51:12 +0530

[-- Attachment #3 --]
[-- Type: message/rfc822, Encoding: 7bit, Size: 0.6K --]

Date: Fri, 13 Mar 2009 14:51:08 +0530
From: root <root@test4.cw.com>
To: subramanya@chipwerks.com
Subject: test
User-Agent: Mutt/1.4.2.1i

these the error iam get bounce back.

[root@test4 ~]# postconf -n
alias_database = hash:/etc/aliases
alias_maps = hash:/etc/aliases
command_directory = /usr/sbin
config_directory = /etc/postfix
daemon_directory = /usr/libexec/postfix
debug_peer_level = 2
html_directory = no
inet_interfaces = all
mail_owner = postfix
mailq_path = /usr/bin/mailq.postfix
manpage_directory = /usr/share/man
mydestination = $myhostname, $mydomain,
mydomain = cw.com
myhostname = test4.cw.com
myorigin = $mydomain
newaliases_path = /usr/bin/newaliases.postfix
queue_directory = /var/spool/postfix
readme_directory = /usr/share/doc/postfix-2.2.8/README_FILES
sample_directory = /usr/share/doc/postfix-2.2.8/samples
sendmail_path = /usr/sbin/sendmail.postfix
setgid_group = postdrop
unknown_local_recipient_reject_code = 550