title: SMTP server response: 550 5.7.1 Unable to relay in - Sending email to a non-company address
body: <p>Here is my code:</p>
  
  <pre><code>&lt;?php
  mail('myemail@gmail.com','Test','Test');
  ?&gt;
  </code></pre>
  
  <p>When sending to a non-company address, I get the following error:</p>
  
  <pre><code>Warning: mail(): SMTP server response: 550 5.7.1 Unable to relay in C:\inetpub\wwwroot\internal_tools\include\mail.php on line 2
  </code></pre>
  
  <p>When switching the email address to my work email, it works just fine. My PHP.ini looks fine, too:</p>
  
  <pre><code>[mail function]
  ; For Win32 only.
  ; http://php.net/smtp
  ;SMTP = localhost
  SMTP = PCMAIL1.mycompany.com
  ; http://php.net/smtp-port
  smtp_port = 25
  
  ; For Win32 only.
  ; http://php.net/sendmail-from
  sendmail_from = no-reply@mycompany.com
  </code></pre>
  
  <p>Even have the site set up in IIS7:</p>
  
  <p>Any ideas?</p>