This occurs because of Sender Policy Framework (SPF) protection which we have placed on your domain. SPF defines what servers are allowed to send email on behalf of your domain name and, by default, only allows the server that your website resides upon to send email using your domain. To allow Google to send email on behalf of your domain, complete the following steps:

1. Login to CWP
2. Choose the "DNS Settings" button
3. If you have more than one domain, then select the domain you're having difficulty with in the list provided. Otherwise skip this step.
4. Look in the list of DNS records shown for one of type "TXT" that starts with v=spf1
5. Click on the name of that record under the "Host" column to edit it
6. Where it says "Enter TXT record" you will need to adjust the text. Immediately after the "v=spf1" copy and paste or type in: include:_spf.google.com
7. Make sure there is one space between the text before and after your addition and click OK to save the record

That's it! You can now send email using Google's mail servers.