Pak syafril mao nanya nich kalo kita send mail ke satu domian kenapa error

ini lognya
Mon 2003-09-29 09:10:04: [184:21] Accepting SMTP connection from
[192.168.100.2]
Mon 2003-09-29 09:10:04: [184:21] --> 220 cbn.net.id ESMTP MDaemon 6.7.7;
Mon, 29 Sep 2003 09:10:04 +0700
Mon 2003-09-29 09:10:04: [184:21] <-- HELO server1
Mon 2003-09-29 09:10:04: [184:21] --> 250 cbn.net.id Hello server1, pleased
to meet you
Mon 2003-09-29 09:10:04: [184:21] <-- MAIL FROM: <[EMAIL PROTECTED]>
Mon 2003-09-29 09:10:04: [184:21] --> 250 <[EMAIL PROTECTED]>, Sender ok
Mon 2003-09-29 09:10:04: [184:21] <-- RCPT TO: <[EMAIL PROTECTED]>
Mon 2003-09-29 09:10:04: [184:21] Can't accept or relay message.
Mon 2003-09-29 09:10:04: [184:21] Sender not authenticated or from trusted
domain/IP and recipient not a valid local account.
Mon 2003-09-29 09:10:04: [184:21] --> 550 <[EMAIL PROTECTED]>, Recipient
unknown
Mon 2003-09-29 09:10:04: [184:21] <-- QUIT
Mon 2003-09-29 09:10:04: [184:21] --> 221 See ya in cyberspace
Mon 2003-09-29 09:10:04: [184:21] SMTP session successful, 81 bytes
transferred.
Mon 2003-09-29 09:10:04: ----------

sdgkan yg di OE:
The message could not be sent because one of the recipients was rejected by
the server. The rejected e-mail address was '[EMAIL PROTECTED]'. Subject 'tes
local mail', Account: '192.168.100.2', Server: '192.168.100.2', Protocol:
SMTP, Server Response: '550 <[EMAIL PROTECTED]>, Recipient unknown', Port:
25, Secure(SSL): No, Server Error: 550, Error Number: 0x800CCC79

tetapi kalo kirim dgn domainnya beda tidak masalah....

Thank atas infonya...
Yos
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