【WinForm】C# 发送Email

发送Email  的条件
1.SmtpClient SMTP 协议 
  即 Host 处理事务的主机或IP地址     //smtp.163.com
     UseDefaultCredentials 使用默认的证书  //false
     DeliveryMethod 指定如何处理代发的电子邮件 //SmtpDeliveryMethod.Network 电子邮件通过网络发到SMTP
     Credentials 设置代发人凭据  //new System.Net.NetworkCredential("用户名","密码")

2.MailMessage 即Email发送消息  （添加到SmtpClient中）
   Subject  主题
   Body   邮件正文
   BodyEncoding 正文编码   //Encoding.UTF8;
   IsBodyHtml是否是HTML 格式  //true
   Priority 电子邮件优先级   // MailPriority.High;
3.Attachment 电子邮件附件   （添加到MailMessage中）
Attachment attach = new Attachment("文件路径",System.Net.Mime.MediaTypeNames.Application.Octet);

整体例子：
                MailMessage message = new MailMessage(famail, dsUserInfo.Tables[0].Rows[j]["Email"].ToString());
                message.Subject = title;
                message.Body = content;
                message.BodyEncoding = Encoding.UTF8;
                message.IsBodyHtml = true;
                message.Priority = MailPriority.High;
                if (!string.IsNullOrEmpty(dsUserInfo.Tables[0].Rows[j]["Attachment"].ToString()))
                {
                    Attachment attach = new Attachment(dsUserInfo.Tables[0].Rows[j]["Attachment"].ToString(), System.Net.Mime.MediaTypeNames.Application.Octet);
                    message.Attachments.Add(attach);   
                }
                try
                {
                    client.Send(message);
                    listBox1.Items.Add("" + dsUserInfo.Tables[0].Rows[j]["SentName"].ToString() + " 的邮件发送成功！");

                }
                catch (Exception ex)
                {
                    listBox1.Items.Add("第" + (j + 1) + "失败！" + ex.ToString());
                }