Mail Relay rejects by other hosts

[jeffrey]

Hi, I currently have dedicated hosting (for IIS) with bodhost, while I have my email (MX) hosting with Google.

In my ASP application, I need to send emails out directly from our mail relay, which I use CDO. It works most of the times, but on certain email addresses, I would get a reject, and my speculation is that I'm sending out the email from a server that does not translate back to the email server.

Is there something I can configure to get less rejects like such?

Thank you.
Jeffrey

A sample reject response:

This is an automatically generated Delivery Status Notification.

Delivery to the following recipients failed.

sample@gmx.net

Final-Recipient: rfc822;sample@gmx.net
Action: failed
Status: 5.5.0
Diagnostic-Code: smtp;550-5.7.1 {mx117} Sorry, your helo has been denied.
550 5.7.1 (GMX - FAQ - Was müssen Administratoren anderer Mailserver beachten?)