Problems sending mail before Domain points moved

I'm new. I followed the FAQ and the message in this Forum on 4/2 about using the 'MX record in the DNS Manager section of the Control Panel'.

My Domain name has NOT been moved to point to the Winhost servers and will not be moved until I can verify the app runs.

Here is the inner Exception I catch and log:

"Mailbox unavailable. The server response was: <[email protected]> No such user here"

Here is the code that throws this exception (X's replaced with real values)

string emailFrom = "[email protected]";
string emailSubj = "Some Subject";
string emailBody = "thebody"
SmtpClient smtpClient = new SmtpClient();
SmtpClient mailClient = new SmtpClient("XXX.internetmailserver.net");
NetworkCredential Credentials = new NetworkCredential("[email protected]", "XXXXXX");

MailMessage smtpMail = new MailMessage(emailFrom, "[email protected], [email protected]", emailSubj, emailBody);

smtpMail.Send(smtpMail); // I catch exception here

I don't understand the error. [email protected] is the email address of where I want the message sent.

I 've configured NOTHING in the email system, but I see that I was given a '[email protected]' when I became a customer.

Any help getting this running would be greatly appreciated.

P

 

That "Mailbox unavailable. No such user here" error usually means authentication is failing.

Take a look at this Knowledge Base article and try altering your authentication method - at least as a test.