Hi all, when im using outlook express to send emails , my email is rejected with the following error: " The message could not be sent because one of the recipients was rejected by the server. The rejected e-mail address was 'user@xxxxxxxxxx'. Subject 'Re: test', Account: 'mail.domain.com', Server: 'mail.domain.com', Protocol: SMTP, Server Response: '550 5.7.1 Unable to relay for user@xxxxxxxxxx', Port: 25, Secure(SSL): No, Server Error: 550, Error Number: 0x800CCC79 " I read the Microsoft Knowledge Base Article - 290808 . I did what was written but the problem did not solved. any one have any idea. Regards, Eng. Amani