C# 发送邮件，QQ企业邮箱测试成功

 using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Text;
 using System.Net.Mail;
 using System.Net;
 namespace ConsoleApplication1
 {
     class Program
     {
         static void Main(string[] args)
         {
             sendMail("**@**.cn","深师家园", "admin@**.com", "admin@***.com", "***", "您好！", "这是一封测试邮件!");
         }

         /// <summary>
         /// 向用户发送邮件
         /// </summary>
         /// <param name="ReceiveUser">接收邮件的用户</param>
         /// <param name="SendUser">发送者显求的邮箱地址,可为空</param>
         /// <param name="DisplayName">收件人显示发件人的联系人名，可为中文</param>
         /// <param name="SendUserName">发送者的邮箱登陆名，可以与发送者地址一样</param>
         /// <param name="UserPassword">发送者的登陆密码</param>
         /// <param name="MailTitle">发送标题</param>
         /// <param name="MailContent">发送的内容</param>
         public static void sendMail(string ReceiveUser,  string DisplayName,string SendUser, string SendUserName, string UserPassword, string MailTitle, string MailContent)
         {
             MailAddress toMail = new MailAddress(ReceiveUser);//接收者邮箱
             MailAddress fromMail = new MailAddress(SendUser, DisplayName);//发送者邮箱
             MailMessage mail = new MailMessage(fromMail, toMail);
             mail.Subject = MailTitle;
             mail.IsBodyHtml = true;//是否支持HTML
             mail.Body = MailContent;
             SmtpClient client = new SmtpClient();
             client.Host = "smtp.exmail.qq.com";//设置发送者邮箱对应的smtpserver
             client.UseDefaultCredentials = false;
             //client.Port = 465;
             client.Credentials = new NetworkCredential(SendUserName, UserPassword);
             client.DeliveryMethod = SmtpDeliveryMethod.Network;
             try
             {
                 client.Send(mail);
             }
             catch(SmtpException ex)
             {
                 Console.Write(ex.Message);
             }
             Console.ReadKey();
         }
     }
 }