ASP.NET发送邮件

MailMessage msg = new MailMessage();
msg.From = settings.SystemEmailAccount;
msg.To = to;
msg.Subject = subject;
msg.Body = body;

if(settings.SmtpAuthenticationRequired)
{
msg.Fields.Add("http://schemas.microsoft.com/cdo/configuration/smtpauthenticate", "1" );
msg.Fields.Add("http://schemas.microsoft.com/cdo/configuration/sendusername", settings.SystemEmailAccount);
msg.Fields.Add("http://schemas.microsoft.com/cdo/configuration/sendpassword", settings.SystemEmailAccountPassword);
}

if(settings.SmtpPort != 25)
{
msg.Fields.Add("http://schemas.microsoft.com/cdo/configuration/smtpserverport", settings.SmtpPort.ToString());
}

if(settings.SmtpUseSSL)
{
msg.Fields.Add("http://schemas.microsoft.com/cdo/configuration/smtpusessl", "1");
}

SmtpMail.SmtpServer = settings.SmtpServer;
SmtpMail.Send(msg);