Can't send mail externally from server

[emailclint@gmail.com]

Hi everyone,

I have a server running Windows 2003. I have set up the POP3 service
according to this guide:
http://www.ilopia.com/Articles/WindowsServer2003/EmailServer.aspx

I've set up the mail server using my domain, configured the email
server with the appropriate settings, added a mail box, and
configured the smtp server. I then configured outlook express just so
I can test the email is working correctly.
I have enabled the setting "My server requires authentication" but I
get this error:

The message could not be sent because one of the recipients was
rejected by the server. The rejected e-mail address was
'xx...@xxxx.co.nz'. Subject 'Test', Account: 'VPS210194', Server:
'xxx.co.nz', Protocol: SMTP, Server Response: '550 5.7.1 Unable to
relay for xxxx...@xxxxx.com', Port: 25, Secure(SSL): No, Server Error:
550, Error Number: 0x800CCC79

Now when I send an email from the account to itself it works perfectly
and incoming mail is fine, however if I try to send email to any
address except one that is on this server then I get that error as
above. I've followed lots of FAQ's etc and searched forums but most
say to turn on the "My server requires authentication" setting and it
should work but mine doesn't.

Any ideas?

 

[emailclint@gmail.com]

On Jul 5, 9:22 am, emailcl...@gmail.com wrote:
> Hi everyone,
>
> I have a server running Windows 2003. I have set up the POP3 service
> according to this guide:http://www.ilopia.com/Articles/WindowsServer2003/EmailServer.aspx
>
> I've set up the mail server using my domain, configured the email
> server with the appropriate settings, added a mail box, and
> configured the smtp server. I then configured outlook express just so
> I can test the email is working correctly.
> I have enabled the setting "My server requires authentication" but I
> get this error:
>
> The message could not be sent because one of the recipients was
> rejected by the server. The rejected e-mail address was
> 'xx...@xxxx.co.nz'. Subject 'Test', Account: 'VPS210194', Server:
> 'xxx.co.nz', Protocol: SMTP, Server Response: '550 5.7.1 Unable to
> relay for xxxx...@xxxxx.com', Port: 25, Secure(SSL): No, Server Error:
> 550, Error Number: 0x800CCC79
>
> Now when I send an email from the account to itself it works perfectly
> and incoming mail is fine, however if I try to send email to any
> address except one that is on this server then I get that error as
> above. I've followed lots of FAQ's etc and searched forums but most
> say to turn on the "My server requires authentication" setting and it
> should work but mine doesn't.
>
> Any ideas?

Can anyone help with this?
Am I in the right group?