Problem With sending email from websit? Plz Help

I have domain name at godaddy registrar the domain Point to external Host IP. & I my MX host at godaddy.

The Problem is:
When i send mail from website with correct email info ( user - pass - smtp ) . I have the error bellow

InnerException: The server rejected one or more recipient addresses. The server response was: 553 sorry, relaying denied from your location [xx.xxx.xxx.xx] (#5.7.1)


How I could solve that error ???

The problem is that the mail server at godaddy (your mx) doesn't trust mail coming from your web server IP. Go daddy's mail server can't accept mail from anywhere, going to anywhere, or it'd be an open relay and be abused by spammers.

If there is configuration you can do on the go daddy hosted mail server to allow relaying from your web server IP, you should do it. Else, you'll need to configure your web server to send mail through a different mail server.

Could I change MX to google App

Sure, but again, google's mail server have to be configured to trust mail coming from your web server.

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Configure Google Apps to properly handle incoming mail from the gateway (Premier and Education Edition only):

1. Log in to the control panel to manage your domain at https://www.google.com/a/mydomain.com (change mydomain.com to your domain name)
2. Select the Service settings tab
3. Select Email from the drop-down menu
4. Add your inbound gateway's IP addresses to the Inbound gateway box. This will improve spam handling. Google will still provide spam filtering on mail from these servers, but proper gateway configuration will reduce the number of messages falsely marked as spam. If you're using Postini, make sure you add these addresses: 64.18.0.0/20 207.126.144.0/20.