网上搜索到的，经测试发现 Hotmail 现在不支持（希望是我理解错了？）Outlook,OutlookExpress 等客户端进行收发信件了。
但还是要抱着对技术学习的态度，我还是把转的东西贴一贴。
核心代码如下：
public void SendMail(string from, string fromName,string to, string subject, string body,string username,string password)
{
// We begin by setting up a quote string (used later) as well generating a mail time stamp: // Quote character. string quote = "\u0022"; // Generate the time stamp. DateTime now = DateTime.Now; string timeStamp = now.ToString("ddd, dd MMM yyyy hh:mm:ss"); // The HTTPMail protocol follows an SMTP-like communication scheme (See RFC 821). Outlook express sends out mail in MIME format, but for demonstrations purposes we simply send a plain text e-mail: // Build the post body. string postBody = null; // Dump mail headers. postBody += "MAIL FROM:<" + from + ">\r\n"; postBody += "RCPT TO:<" + to + ">\r\n"; postBody += "\r\n"; postBody += "From: " + quote + fromName + quote + " <" + from + ">\r\n"; postBody += "To: <" + to + ">\r\n"; postBody += "Subject: " + subject +"\r\n"; postBody += "Date: " + timeStamp + " -0000\n"; postBody += "\r\n"; // Dump mail body. postBody += body; // To send the mail, we need to set the Content-Type request header to message/rfc821, indicating that this request contains a body which follows RFC 821. We POST the request body generated above to the sendmsg URL obtained during connection time: xmlHttp_ = new XMLHTTP(); // Open the connection. xmlHttp_.open("POST", serverUrl, false, username,password); // Send the request. xmlHttp_.setRequestHeader("Content-Type", "message/rfc821"); xmlHttp_.send(postBody); MessageBox.Show( xmlHttp_.statusText ); //xmlHttp_.responseText;
}原代码在最后一行是用 xmlHttp_.responseText 实际上读不出数据，而用 statusText, 可以收到 Hotmail 的响应内容：
---------------------------Access to Hotmail via Outlook and Outlook Express now requires a subscription. Please sign up at http://upgrade.msn.com---------------------------当然还有其他变通的办法让你可以使用 hotmail 发信件的。。。。
