Hi,

I try to send a mail using System.Web.Mail.SmtpMail via the local (virtual)
SMTP server like this:

System.Net.Mail.SmtpClient smtpClient = new
System.Net.Mail.SmtpClient("localhost");
smtpClient.Credentials =
System.Net.CredentialCache.DefaultNetworkCredentials;
smtpClient.Send("test@gmx.de", "test@gmx.de", "Test", "This is as test"); //
Exception

"test@gmx.de" is an existing E-Mail-Address.

Send throws the error "Unable to relay for test@gmx.de"!???

Using the old style SmtpMail class the mail is sent without exception:

System.Web.Mail.SmtpMail.SmtpServer = "";
System.Web.Mail.SmtpMail.Send("test@gmx.de", "test@gmx.de", "Test", "This is
as test"); // OK

Does anyone know the source of this error?