VS2005 (asp.net2.0) easy to send mail. __.net

VS2005 (asp.net2.0) easy to send mail.

In asp.net 2.0 it is easy to develop SMTP email messages. Unlike an ASP, you have to register JMail controls or something.

You need to reference the following namespaces:
Using System.Net.Mail;
Using System.Net;

The following is a message sent via smtp.126.com. Smtp.126.com requires authentication.
protected void Sendmail_click (object sender, EventArgs e)
{
String to = "xpnew@126.com";
String from = "xpnew@126.com";
String subject = mailtitle.text;//"Using the new SMTP client.";
String BODY = mailbody.text;//@ ' Using This new feature, your can send an e-mail message from a application very easily. ";
MailMessage message = new MailMessage (from, to, subject, body);
SmtpClient client = new SmtpClient ("smtp.126.com", 25);
Credentials are necessary if the server requires the client
To authenticate before it'll send e-Mail on the client ' s behalf.
Client. Credentials = credentialcache.defaultnetworkcredentials;
Client. Credentials = new NetworkCredential ("Xpnew", "xxxxxx");//This is changed to your own account and password.
Client. Send (message);
}

The following

is sent through the native (IIS-brought SMTP server) without authentication.
This is also useful, usually in the actual work encountered in the development of the Enterprise internal Web applications (such as OA), then have to use the internal SMTP server.
It's a pity that I didn't pass the test all afternoon. (Cannot relay to the Internet)
    protected void Sendfromlocal_click (object sender, EventArgs e)
     {
        string to = ' xpnew@126.com ';
        string from = "xpnew@126.com";
        String subject = mailtitle.text;//"Using the new SMTP client.";
        String BODY = mailbody.text;//@ ' Using This new feature, your can send an E Mail message from a application very easily. ";
        MailMessage message = new MailMessage (from, to, subject, body);
        SmtpClient client = new SmtpClient ("localhost");

Credentials are necessary if the server requires the client
To authenticate before it'll send e-Mail on the client ' s behalf.
Client. Credentials = credentialcache.defaultnetworkcredentials;
Client. Send (message);
}

There may be some problems when sending through this machine.
1, "Mailbox is not available." Server response: 5.7.1 Unable to relay for xpnew@126.com "
Solution:
In IIS, right-click the default SMTP virtual server, select Properties, switch to the Access page, click the "Relay" button, and in the pop-up box, select "Except the list below" to determine.
2, the mail sent out, but the other side is not received.
The reason for the moment has not been found. Looked up some information on the Internet, as if the other side of the server was identified as spam.

Resources:

1, Msdn:.net Framework class Library Smtpclient.credentials properties

2, vs2003 and vs2005 send SMTP mail (downmoon original)
Http://dev.21tx.com/2006/01/22/10217.html

3, Error: 5.7.1

Http://blog.csdn.net/beimuaihui/archive/2007/08/12/1739409.aspx

4. Configure remote domains for Internet information Services SMTP mail relay servers in Win2003
Http://www.knowsky.com/341533.html