>>>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

What we do is we have only one machine open for relay, and we run on it a program that reads a table with the e-mail requests and full-fills it, so the programs instead of sending e-mail directly they add records to this table.