This is identical to the 550 Relaying Denied error message, only this time the IP address is blocked by the Mail Abuse Prevention System.

In order to send email through Avvanta's network while connected to another ISP you must configure your email program to authenticate to the mail server before sending.

To configure Outlook or Outlook Express to authenticate, click on Tools, then Accounts. From the Accounts window, click on the Mail tab. Click one time on the mail.avvanta.com account entry and then click on the Properties button. Click on the Servers tab and check the checkbox labelled "My server requires authentication" and click on Ok. Close the Accounts window by clicking on the Close button. Each time you send out mail now, Outlook will log in to our mail server and allow you to send mail out.