c# 发送Email的2中方式

先来第一种

 // 版权所有 ZhuoYue Co.,Ltd 卓越一通秘密信息
 // 文件名称：MyEmailByCDO.cs
 // 作　　者：huangzh
 // 创建日期：2015-08-20 16:18:27
 // 功能描述：发送邮件MyEmailByCDO
 // 任务编号：
 using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Text;

 namespace ZhuoYueE.Bpc.Core.Email
 {

     /// <summary>
     /// 功能描述:发送邮件MyEmailByCDO
     /// 作　　者:huangzh
     /// 创建日期:2015-08-20 16:18:24
     /// 任务编号:
     /// </summary>
     public class MyEmailByCDO
     {
         ///<summary>
         /// 构造函数
         ///</summary>
         ///<param name="strserver">发件箱的邮件服务器地址</param>
         ///<param name="strtoMail">收件人地址（可以是多个收件人，程序中是以“;"进行区分的）</param>
         ///<param name="strfromMail">发件人地址</param>
         ///<param name="strsubject">邮件标题</param>
         ///<param name="stremailBody">邮件内容（可以以html格式进行设计）</param>
         ///<param name="strpassword">发件人邮箱密码</param>
         ///<param name="intport">发送邮件所用的端口号（htmp协议默认为25）</param>
         ///<param name="blnsslEnable">true表示对邮件内容进行socket层加密传输，false表示不加密</param>
         ///<param name="strCC">抄送人</param>
         public static void SendMyEmailByCDO(string strserver,
             string strtoMail,
             string strfromMail,
             string strsubject,
             string stremailBody,
             string strpassword,
             int intport,
             bool blnsslEnable,
             string strCC)
         {
             SendMyEmailByCDO(strserver,
              strtoMail,
              strfromMail,
              strsubject,
              stremailBody,
              strpassword,
              intport,
              blnsslEnable,
              strCC,
              null);
         }

         ///<summary>
         /// 构造函数
         ///</summary>
         ///<param name="strserver">发件箱的邮件服务器地址</param>
         ///<param name="strtoMail">收件人地址（可以是多个收件人，程序中是以“;"进行区分的）</param>
         ///<param name="strfromMail">发件人地址</param>
         ///<param name="strsubject">邮件标题</param>
         ///<param name="stremailBody">邮件内容（可以以html格式进行设计）</param>
         ///<param name="strpassword">发件人邮箱密码</param>
         ///<param name="intport">发送邮件所用的端口号（htmp协议默认为25）</param>
         ///<param name="blnsslEnable">true表示对邮件内容进行socket层加密传输，false表示不加密</param>
         /// <param name="strCC">抄送人</param>
         /// <param name="files">附件</param>
         public static void SendMyEmailByCDO(
             string strserver,
             string strtoMail,
             string strfromMail,
             string strsubject,
             string stremailBody,
             string strpassword,
             int intport,
             bool blnsslEnable,
             string strCC,
             List<string> files)
         {
             string stryourEmail = strfromMail;
             CDO.Message message = new CDO.Message();
             CDO.IConfiguration configuration = message.Configuration;
             ADODB.Fields fields = configuration.Fields;

             Console.WriteLine(String.Format("Configuring CDO settings..."));

             ADODB.Field field = fields["http://schemas.microsoft.com/cdo/configuration/smtpserver"];
             field.Value = strserver;

             field = fields["http://schemas.microsoft.com/cdo/configuration/smtpserverport"];
             field.Value = intport;

             field = fields["http://schemas.microsoft.com/cdo/configuration/sendusing"];
             field.Value = CDO.CdoSendUsing.cdoSendUsingPort;

             field = fields["http://schemas.microsoft.com/cdo/configuration/smtpauthenticate"];
             field.Value = CDO.CdoProtocolsAuthentication.cdoBasic;

             field = fields["http://schemas.microsoft.com/cdo/configuration/sendusername"];
             field.Value = stryourEmail;

             field = fields["http://schemas.microsoft.com/cdo/configuration/sendpassword"];
             field.Value = strpassword;

             field = fields["http://schemas.microsoft.com/cdo/configuration/smtpusessl"];
             field.Value = blnsslEnable.ToString().ToLower();

             fields.Update();

             Console.WriteLine(String.Format("Building CDO Message..."));

             message.From = stryourEmail;
             message.To = strtoMail;
             message.Subject = strsubject;
             message.BodyPart.Charset = "utf-8";

             if (!string.IsNullOrEmpty(strCC))
             {
                 message.CC = strCC;
             }

             message.HTMLBody = stremailBody;
             if (files != null)
             {
                 foreach (string stritem in files)
                 {
                     message.AddAttachment(stritem);
                 }
             }

             Console.WriteLine(String.Format("Attempting to connect to remote server..."));

             // Send message.
             message.Send();
         }
     }
 }

第二种

 // 版权所有 ZhuoYue Co.,Ltd 卓越一通秘密信息
 // 文件名称：MyEmail.cs
 // 作　　者：huangzh
 // 创建日期：2015-08-20 08:37:07
 // 功能描述：邮件辅助类
 // 任务编号：
 using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Text;
 using System.Net.Mail;
 using System.Net.Mime;
 using System.IO;

 namespace ZhuoYueE.Bpc.Core.Email
 {
     /// <summary>
     /// 功能描述:邮件辅助类
     /// 作　　者:huangzh
     /// 创建日期:2015-08-20 08:36:52
     /// 任务编号:
     /// </summary>
     public class MyEmailBySmtp
     {
         /// <summary>
         /// 主要处理发送邮件的内容（如：收发人地址、标题、主体、图片等等）
         /// </summary>
         private MailMessage m_mailMessage;
         /// <summary>
         /// 主要处理用smtp方式发送此邮件的配置信息（如：邮件服务器、发送端口号、验证方式等等）
         /// </summary>
         private SmtpClient m_smtpClient;
         /// <summary>
         /// 发送邮件所用的端口号（htmp协议默认为25）
         /// </summary>
         private int m_intsenderPort;
         /// <summary>
         /// 发件箱的邮件服务器地址（IP形式或字符串形式均可）
         /// </summary>
         private string m_strsenderServerHost;
         /// <summary>
         /// 发件箱的密码
         /// </summary>
         private string m_strsenderPassword;
         /// <summary>
         /// 发件箱的用户名（即@符号前面的字符串，例如：hello@163.com，用户名为：hello）
         /// </summary>
         private string m_strsenderUsername;
         /// <summary>
         /// 是否对邮件内容进行socket层加密传输
         /// </summary>
         private bool m_blnsnableSsl;
         /// <summary>
         /// 抄送
         /// </summary>
         private string m_strCC;

         ///<summary>
         /// 构造函数
         ///</summary>
         ///<param name="strserver">发件箱的邮件服务器地址</param>
         ///<param name="strtoMail">收件人地址（可以是多个收件人，程序中是以“;"进行区分的）</param>
         ///<param name="strfromMail">发件人地址</param>
         ///<param name="strsubject">邮件标题</param>
         ///<param name="stremailBody">邮件内容（可以以html格式进行设计）</param>
         ///<param name="strusername">发件箱的用户名（即@符号前面的字符串，例如：hello@163.com，用户名为：hello）</param>
         ///<param name="strpassword">发件人邮箱密码</param>
         ///<param name="intport">发送邮件所用的端口号（htmp协议默认为25）</param>
         ///<param name="blnsslEnable">true表示对邮件内容进行socket层加密传输，false表示不加密</param>
         ///<param name="strCC">抄送</param>
         public MyEmailBySmtp(
             string strserver,
             string strtoMail,
             string strfromMail,
             string strsubject,
             string stremailBody,
             string strusername,
             string strpassword,
             int intport,
             bool blnsslEnable,
             string strCC)
         {
             try
             {

                 m_mailMessage = new MailMessage();
                 m_mailMessage.To.Add(strtoMail);
                 m_mailMessage.From = new MailAddress(strfromMail, strfromMail, Encoding.UTF8);
                 m_mailMessage.Subject = strsubject;
                 m_mailMessage.Body = stremailBody;
                 m_mailMessage.IsBodyHtml = true;
                 m_mailMessage.BodyEncoding = System.Text.Encoding.UTF8;
                 m_mailMessage.Priority = MailPriority.High;
                 m_mailMessage.CC.Add(strCC);
                 this.m_strsenderServerHost = strserver;
                 this.m_strsenderUsername = strusername;
                 this.m_strsenderPassword = strpassword;
                 this.m_intsenderPort = intport;
                 this.m_blnsnableSsl = blnsslEnable;
             }
             catch
             {
                 throw;
             }
         }

         ///<summary>
         /// 添加附件
         ///</summary>
         ///<param name="strattachmentsPath">附件的路径集合，以分号分隔</param>
         public void AddAttachments(string strattachmentsPath)
         {
             try
             {
                 //以什么符号分隔可以自定义
                 string[] path = strattachmentsPath.Split(';');
                 Attachment data;
                 ContentDisposition disposition;
                 for (int i = ; i < path.Length; i++)
                 {
                     data = new Attachment(path[i], MediaTypeNames.Application.Octet);
                     disposition = data.ContentDisposition;
                     disposition.CreationDate = File.GetCreationTime(path[i]);
                     disposition.ModificationDate = File.GetLastWriteTime(path[i]);
                     disposition.ReadDate = File.GetLastAccessTime(path[i]);
                     m_mailMessage.Attachments.Add(data);
                 }

             }
             catch
             {
                 throw;
             }
         }

         ///<summary>
         /// 邮件的发送
         ///</summary>
         public void Send()
         {
             try
             {

                 if (m_mailMessage != null)
                 {
                     m_smtpClient = new SmtpClient();
                     m_smtpClient.Host = this.m_strsenderServerHost;
                     m_smtpClient.Port = m_intsenderPort;
                     m_smtpClient.UseDefaultCredentials = true;
                     m_smtpClient.EnableSsl = this.m_blnsnableSsl;
                     m_smtpClient.Credentials = new System.Net.NetworkCredential(this.m_strsenderUsername, this.m_strsenderPassword);
                     m_smtpClient.DeliveryMethod = System.Net.Mail.SmtpDeliveryMethod.Network;

                     m_smtpClient.Send(m_mailMessage);
                 }

             }
             catch
             {
                 throw;
             }
         }
     }
 }

为什么这里写了2中方式呢？？？

我相信大多数人发送邮件使用第二种，但是有时候第二种方式是发不出去的，那么什么情况发布出去呢？？？

答曰：

当你使用公司内部邮件服务器发送邮件，并且需要SSL加密的时候，你就呵呵一下，第二种不行了，然后你可以尝试第一种了，最少我这里是这种情况。

我现在发送邮件的一般都用第一种的代码了。

有什么问题，请留言吧。