I am getting the folling error on my frontend server: A non-delivery report with a status code of 5.3.5 was generated for recipient. Causes: A looping condition was detected. (The server is configured to route mail back to itself). If you have multiple SMTP Virtual Servers configured on your Exchange server, make sure they are defined by a unique incoming port and that the outgoing SMTP port configuration is valid to avoid looping between local virtual servers. Solution: Check the configuration of the virtual servers connectors for loops and ensure each virtual server is defined by a unique incoming port. I have followed the sugestions by technet regarding this issue to no avail. Any help would be appreciated. Thank you, Fosster

Can you provide more detail on who you are sending to? Are you using a AD contact to send the mail?