.net (c#)实现发送外部邮件的实例

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Net.Mail;

public partial class testSendMail : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        string strFrom = "xiaoxueli707325@126.com";
        string strTo = "shirlly.liao@163.com";
        string strSubject = "webtest";
        string strBody = "测试";
        System.Net.Mail.MailMessage message = new System.Net.Mail.MailMessage(strFrom, strTo, strSubject, strBody);
        message.BodyEncoding = System.Text.Encoding.UTF8;
        message.IsBodyHtml = true;

        SendSMTPEMail("smtp.126.com", "xiaoxueli707325@126.com", "111111", message);

    }
    public void SendSMTPEMail(string strSmtpServer, string strFrom, string strFromPass, MailMessage message)
    {
        try
        {
            SmtpClient client = new SmtpClient(strSmtpServer);
            client.UseDefaultCredentials = true;
            client.Credentials = new System.Net.NetworkCredential(strFrom, strFromPass);
            client.DeliveryMethod = SmtpDeliveryMethod.Network;
            
            client.Send(message);
        }
        catch (Exception ex)
        {
            throw new Exception(ex.Message);
        }
    }
}

注意：
1、确保strFrom的值和strSmtpServer的值一致，否之会报Send Error:不允许使用邮箱名称。 服务器响应为: You are not authorized to send mail, authentication is required。的错误
2、确保用于发送邮件的邮箱不是刚注册的邮箱，而要用有提供SMTP服务的邮箱的帐号和密码，否则会报邮箱不可以用的错误

3、下面两句的书写的顺序不能颠倒

client.UseDefaultCredentials = true;
client.Credentials = new System.Net.NetworkCredential(strFrom, strFromPass);

否则会报这样的错误

4、注意126的域名是smtp.126.com
163的域名是smtp.163.com