Topic: Cannot send e-mail.

[nadzry]

I use SME Server 6.0. I managed to migrate it from SME server 5.6. Everything run smoothly except that i cannot send mail out...I got this error message....
     The message could not be sent because one of     the recipients was rejected by the server. The rejected e-mail address was 't68n@yahoo.com'. Subject 'nhfehif', Account: 'Trustgate Mail', Server: 'mail.msctrustgate.com', Protocol: SMTP, Server Response: '553 Sorry, that domain isn't in my list of allowed rcpthosts.', Port: 25, Secure(SSL): No, Server Error: 553, Error Number: 0x800CCC79

Anyone can help me???