>>Test machine in my office sends E-Mail perfectly using wwiipstuff. At client site they are using Small Business Server 2011 running Exchange Server 2010
>>
>>Clients machine will send an E-mail thru Outlook with no problems. But my program fails using what seems to be the same credentials.
>>
>>Are there known gotcha's with this setup?
>
>Their Exchange needs to be set to allow SMTP Relay from the IP address of the machine that is sending the mail.

Thanks Bill. Working on that right now. They are reluctant to have an "open" relay for the 13 machines that need to send this E-Mail stuff

Ken