Php mail error

[puk284]

Hi,
I ve got php set up on my localhost using IIS 7 which all works fine. iv also got Argosoft mail server.net free setup as well. The problem i have is that when i try to send an e-mail using a php e-mail script i get the following error:

PHP Warning: mail(): SMTP server response: 510 User not local. We don't relay in C:\inetpub\wwwroot\em.php on line 15

Please does anyone know what the solution is. Thank you in advance for your help

[$tatic]

SMTP Error 510 simply represents bad email address. This status code is generated by the sender’s local mail server when the addressee provided in the email’s TO, CC, or BCC fields does not exist in your organization’s email system. So to solve this problem simply tick mark the checkbox: "do not require authentication if user is local".