I am unable to send mails few of the domains.

can any one help me on this issue.


Reporting-MTA: dns; mail.solarsemiconductor.com
X-Postfix-Queue-ID: C4BC420E0239
X-Postfix-Sender: rfc822; madhusudhan.pilli@solarsemiconductor.com
Arrival-Date: Fri, 6 Jun 2008 09:37:35 +0530 (IST)

Final-Recipient: rfc822; Angelito.Juan@sunpowercorp.com
Original-Recipient: rfc822;Angelito.Juan@sunpowercorp.com
Action: failed
Status: 5.7.1
Remote-MTA: dns; mail9.sunpowercorp.com
Diagnostic-Code: smtp; 550 5.7.1 <Angelito.Juan@sunpowercorp.com>... Relaying
denied. Proper authentication required.

Final-Recipient: rfc822; Yevgeny.Meydbray@sunpowercorp.com
Original-Recipient: rfc822;Yevgeny.Meydbray@sunpowercorp.com
Action: failed
Status: 5.7.1
Remote-MTA: dns; mail9.sunpowercorp.com
Diagnostic-Code: smtp; 550 5.7.1 <Yevgeny.Meydbray@sunpowercorp.com>...
Relaying denied. Proper authentication required.