The following addresses had permanent fatal errors -----
<xxxxxxxxx@yahoo.com>
(reason: 550 5.7.1 message content rejected)

----- Transcript of session follows -----
... while talking to mail.skyinet.net.:
>>> DATA
<<< 550 5.7.1 message content rejected
554 5.0.0 Service unavailable

Final-Recipient: RFC822; xxxxxxxxx.com
Action: failed
Status: 5.7.1
Remote-MTA: DNS; mail.skyinet.net
Diagnostic-Code: SMTP; 550 5.7.1 message content rejected
Last-Attempt-Date: Sat, 15 Sep 2012 11:00:01 +0800







can someone help me with this. I cant send email outside our domain, it always return. please help me!

It clearly reads "5.7.1 message content rejected" so start by investigating what you're actually sending and try sending a plain text body test message like "Hello World" first?

Sounds like this is server related.