SMTP - Hotmail Bulk Mail Problem

[just-me]

Hi,
I am trying to send an email:

System.Web.Mail.MailMessage Message = new System.Web.Mail.MailMessage();
Message.To = "xx**@hotmail.com";
Message.From = xx*@xxx.net;
Message.Body = txtBody.Text;
Message.Subject = txtSubject.Text;
Message.Fields.Add("http://schemas.microsoft.com/cdo/configuration/smtpauthe
nticate", "1"); //basic authentication

Message.Fields.Add("http://schemas.microsoft.com/cdo/configuration/sendusern
ame", "xxxx"); //set your username here

Message.Fields.Add("http://schemas.microsoft.com/cdo/configuration/sendpassw
ord", "xxx"); //set your password here

System.Web.Mail.SmtpMail.SmtpServer = "smtp.xxxx.net";
System.Web.Mail.SmtpMail.Send(Message);

But the message keeps going into my Hotmail Bulk Mail folder.
How do I send a message that does not go into the Hotmail Folder?
I added authentication, but it seems useless in this case. I can do the same
without the authentication.
Any clues? Please help!

Thanks,
Simone