C# 实现邮件发送：QQ邮箱及SSL配置示例

if (smptPort == 465)
            {
                System.Web.Mail.MailMessage mail = new System.Web.Mail.MailMessage();
                mail.To = toUserName;
                mail.From = smtpUserName;
                mail.Subject = subject;
                mail.BodyFormat = System.Web.Mail.MailFormat.Html;
                mail.Body = body;

                mail.Fields.Add("http://schemas.microsoft.com/cdo/configuration/smtpauthenticate", "1"); //basic authentication  
                mail.Fields.Add("http://schemas.microsoft.com/cdo/configuration/sendusername", smtpUserName); //set your username here  
                mail.Fields.Add("http://schemas.microsoft.com/cdo/configuration/sendpassword", smtpPassword); //set your password here  
                mail.Fields.Add("http://schemas.microsoft.com/cdo/configuration/smtpserverport", 465);//set port  
                mail.Fields.Add("http://schemas.microsoft.com/cdo/configuration/smtpusessl", "true");//set is ssl  
                System.Web.Mail.SmtpMail.SmtpServer = smtpServer;
                System.Web.Mail.SmtpMail.Send(mail);
            }
            else
            {
                MailMessage msg = new MailMessage();
                msg.To.Add(toUserName);//收件人地址 
                                       //msg.CC.Add("cc@qq.com");//抄送人地址  
                msg.From = new MailAddress(smtpUserName);//发件人邮箱，名称  
                msg.Subject = subject;//邮件标题  
                msg.SubjectEncoding = Encoding.UTF8;//标题格式为UTF8  
                msg.Body = body;//邮件内容
                                //用smtpclient对象里attachments属性，添加上面设置好的myattachment，url绝对路径 
                if (fileUrl != null) msg.Attachments.Add(new Attachment(fileUrl));
                msg.BodyEncoding = Encoding.UTF8;//内容格式为UTF8
                msg.IsBodyHtml = true;