I have a problem with my DotNetNuke program. I have a 1&1 VPS Server and trying to set up the SMTP server. I have typed in the smtp server and it says it was sent and it only lets me send to my local email address. I have used SMTP authentication and it still does not work.

Here is the error:

Message: System.Net.Mail.SmtpException: Bad sequence of commands. The server response was: This mail server requires authentication when attempting to send to a non-local e-mail address. Please check your mail client settings or contact your administrator to verify that the domain or address is defined for this server
 

I'll assume you have already set up a mail box for the Admin account -

In Host Settings, SMTP section, for SMTP Authentication, select "Basic".  Enter a valid email address and password (we use the admin account's email).  Be sure you have the correct address for your SMTP server in the "SMTP Server and Port". Then click Update without first clicking on Test (or the password gets erased).  Now click on the "Test" to see if it works.  The email address you entered for Admin should receive a short test email.

I saw where the OP said they had used SMTP authentication and it did not work.  This may be caused by the password entry bug I reported a while back.  If you enter an email address and password, and click Test, it works but the password is wiped out.  You then click Update and a blank password is stored.  Thus my specific instructions.

The error message posted to me indicates that authentication is not being used.