SMTP email from C#

￡神魔★判官ぃ 2021-12-13 00:59 240阅读 0赞

/// <summary>
 /// 一人一附件发送邮件
 /// 2017-05-17 涂聚文 GeovinDu
 /// </summary>
 /// <param name="To">接收邮件人</param>
 /// <param name="Subject">邮件标题</param>
 /// <param name="Msg">邮件内容</param>
 /// <param name="bodyHtml">是否網頁</param>
 /// <param name="AttachmentStream"></param>
 /// <param name="AttachmentFileName">附件</param>
 /// <returns></returns>
 public static bool SendEmaildu(string To, string Subject, string Msg, bool bodyHtml, MemoryStream AttachmentStream,string AttachmentFileName)
 {
 bool SendOk = false;
 try
 {
 System.Net.Mail.MailMessage newMsg = new System.Net.Mail.MailMessage(System.Configuration.ConfigurationManager.AppSettings["mailCfg"], To, Subject, Msg);
 newMsg.BodyEncoding = System.Text.Encoding.UTF8;
 newMsg.HeadersEncoding = System.Text.Encoding.UTF8;
 newMsg.SubjectEncoding = System.Text.Encoding.UTF8;
 
 System.Net.Mail.SmtpClient smtpClient = new System.Net.Mail.SmtpClient();
 //smtpClient.Credentials = new NetworkCredential("geovindu@dusystem.com","888888");
 //smtpClient.Port = 25;
 //smtpClient.EnableSsl = false;
 if (AttachmentStream != null && AttachmentFileName != null)
 {
 
 // ADD AN ATTACHMENT.
 //String sFile = @"C:\Source\LNS_IS.TXT";
 //MailAttachment oAttch = new MailAttachment(sFile, MailEncoding.Base64);
 //string filePath = @"C:\TestEmail\SKYPE11月黑咭生日會員.xls";
 //MemoryStream memStream = new MemoryStream();
 //using (FileStream fileStream = File.OpenRead(filePath))
 //{
 
 // memStream.SetLength(fileStream.Length);
 // fileStream.Read(memStream.GetBuffer(), 0, (int)fileStream.Length);
 //}
 
 newMsg.Attachments.Add(new Attachment(AttachmentStream, AttachmentFileName)); //MediaTypeNames.Image.Jpeg) 
 
 
 //System.Net.Mail.Attachment attachment = new System.Net.Mail.Attachment(AttachmentStream, AttachmentFileName);
 //System.Net.Mime.ContentDisposition disposition = attachment.ContentDisposition;
 //disposition.FileName = AttachmentFileName;
 //disposition.DispositionType = System.Net.Mime.DispositionTypeNames.Attachment;
 //newMsg.Attachments.Add(attachment);
 
 }
 newMsg.IsBodyHtml = bodyHtml;
 
 smtpClient.Send(newMsg);
 SendOk = true;
 //return SENT_OK;
 }
 catch (Exception ex)
 {
 ex.Message.ToString();
 AttachmentStream.Close();
 SendOk = false;
 //"Error: " + ex.Message + " Inner Exception: "+ ex.InnerException;
 
 
 }
 AttachmentStream.Close();
 return SendOk;
 
 }
 /// <summary>
 /// 一人一附件发送邮件
 /// 2017-05-17 涂聚文 GeovinDu
 /// </summary>
 /// <param name="To">接收邮件人</param>
 /// <param name="Subject">邮件标题</param>
 /// <param name="Msg">邮件内容</param>
 /// <param name="bodyHtml">是否網頁</param>
 /// <param name="AttachmentFileName">附件</param>
 /// <returns></returns>
 public static bool SendEmaildu(string To, string Subject, string Msg, bool bodyHtml, string AttachmentFileName)
 {
 MemoryStream AttachmentStream = new MemoryStream();
 bool SendOk = false;
 try
 {
 System.Net.Mail.MailMessage newMsg = new System.Net.Mail.MailMessage(System.Configuration.ConfigurationManager.AppSettings["mailCfg"], To, Subject, Msg);
 newMsg.BodyEncoding = System.Text.Encoding.UTF8;
 newMsg.HeadersEncoding = System.Text.Encoding.UTF8;
 newMsg.SubjectEncoding = System.Text.Encoding.UTF8;
 
 System.Net.Mail.SmtpClient smtpClient = new System.Net.Mail.SmtpClient();
 //smtpClient.Credentials = new NetworkCredential("geovindu@dusystem.com","888888");
 //smtpClient.Port = 25;
 //smtpClient.EnableSsl = false;
 if (AttachmentStream != null && AttachmentFileName != null)
 {
 
 // ADD AN ATTACHMENT.
 //String sFile = @"C:\Source\LNS_IS.TXT";
 //MailAttachment oAttch = new MailAttachment(sFile, MailEncoding.Base64);
 //string filePath = @"C:\TestEmail\SKYPE11月黑咭生日會員.xls";
 //MemoryStream memStream = new MemoryStream();
 //using (FileStream fileStream = File.OpenRead(filePath))
 //{
 
 // memStream.SetLength(fileStream.Length);
 // fileStream.Read(memStream.GetBuffer(), 0, (int)fileStream.Length);
 //}
 
 newMsg.Attachments.Add(new Attachment(AttachmentStream, AttachmentFileName)); //MediaTypeNames.Image.Jpeg) 
 
 
 //System.Net.Mail.Attachment attachment = new System.Net.Mail.Attachment(AttachmentStream, AttachmentFileName);
 //System.Net.Mime.ContentDisposition disposition = attachment.ContentDisposition;
 //disposition.FileName = AttachmentFileName;
 //disposition.DispositionType = System.Net.Mime.DispositionTypeNames.Attachment;
 //newMsg.Attachments.Add(attachment);
 
 }
 newMsg.IsBodyHtml = bodyHtml; 
 smtpClient.Send(newMsg);
 SendOk = true;
 //return SENT_OK;
 }
 catch (Exception ex)
 {
 ex.Message.ToString();
 AttachmentStream.Close();
 SendOk = false;
 //"Error: " + ex.Message + " Inner Exception: "+ ex.InnerException;
 
 
 }
 AttachmentStream.Close();
 return SendOk;
 
 }
 
 /// <summary>
 /// 一人多附件发送邮件
 /// 2019-06-18 涂聚文 GeovinDu
 /// </summary>
 /// <param name="To">接收邮件人</param>
 /// <param name="Subject">邮件标题</param>
 /// <param name="Msg">邮件内容</param>
 /// <param name="bodyHtml">是否網頁</param>
 /// <param name="AttachmentFiles">多附件</param>
 /// <returns></returns>
 public static bool SendEmailduFiles(string To, string Subject, string Msg, bool bodyHtml, List<string> AttachmentFiles)
 {
 MemoryStream AttachmentStream = new MemoryStream();
 bool SendOk = false;
 try
 {
 System.Net.Mail.MailMessage newMsg = new System.Net.Mail.MailMessage(System.Configuration.ConfigurationManager.AppSettings["mailCfg"], To, Subject, Msg);
 newMsg.BodyEncoding = System.Text.Encoding.UTF8;
 newMsg.HeadersEncoding = System.Text.Encoding.UTF8;
 newMsg.SubjectEncoding = System.Text.Encoding.UTF8;
 
 System.Net.Mail.SmtpClient smtpClient = new System.Net.Mail.SmtpClient();
 //smtpClient.Credentials = new NetworkCredential("geovindu@dusystem.com","888888");
 //smtpClient.Port = 25;
 //smtpClient.EnableSsl = false;
 
 
 
 if (AttachmentStream != null && AttachmentFiles != null)
 {
 
 
 foreach (string filename in AttachmentFiles)
 {
 newMsg.Attachments.Add(new Attachment(AttachmentStream, filename)); //MediaTypeNames.Image.Jpeg) 
 
 } 
 
 }
 newMsg.IsBodyHtml = bodyHtml; 
 smtpClient.Send(newMsg);
 SendOk = true;
 }
 catch (Exception ex)
 {
 ex.Message.ToString();
 AttachmentStream.Close();
 SendOk = false;
 }
 AttachmentStream.Close();
 return SendOk;
 }
 
 /// <summary>
 /// 多人多附件发送邮件
 /// 不考虑统计每封邮件发送状态（另外考虑完善代码）
 /// 2019-06-18 涂聚文 GeovinDu
 /// </summary>
 /// <param name="Tos">多人接收邮件人</param>
 /// <param name="Subject">邮件标题</param>
 /// <param name="Msg">邮件内容</param>
 /// <param name="bodyHtml">是否網頁</param>
 /// <param name="AttachmentFiles">多附件</param>
 /// <returns></returns>
 public static bool SendEmailsAndFiles(List<string> Tos, string Subject, string Msg, bool bodyHtml, List<string> AttachmentFiles)
 {
 MemoryStream AttachmentStream = new MemoryStream();
 bool SendOk = false;
 List<Attachment> all = new List<Attachment>();
 try
 {
 if (AttachmentStream != null && AttachmentFiles != null)
 {
 foreach (string filename in AttachmentFiles)
 {
 
 all.Add(new Attachment(AttachmentStream, filename));
 }
 }
 if (Tos.Count > 0)
 {
 
 
 foreach (string To in Tos)
 {
 System.Net.Mail.MailMessage newMsg = new System.Net.Mail.MailMessage(System.Configuration.ConfigurationManager.AppSettings["mailCfg"], To, Subject, Msg);
 newMsg.BodyEncoding = System.Text.Encoding.UTF8;
 newMsg.HeadersEncoding = System.Text.Encoding.UTF8;
 newMsg.SubjectEncoding = System.Text.Encoding.UTF8;
 System.Net.Mail.SmtpClient smtpClient = new System.Net.Mail.SmtpClient();
 //smtpClient.Credentials = new NetworkCredential("geovindu@dusystem.com","888888");
 //smtpClient.Port = 25;
 //smtpClient.EnableSsl = false;
 if (AttachmentStream != null && AttachmentFiles != null)
 {
 foreach (Attachment attname in all)
 {
 newMsg.Attachments.Add(attname); //MediaTypeNames.Image.Jpeg) 
 
 }
 }
 newMsg.IsBodyHtml = bodyHtml; 
 smtpClient.Send(newMsg);
 SendOk = true;
 }
 }
 }
 catch (Exception ex)
 {
 ex.Message.ToString();
 AttachmentStream.Close();
 SendOk = false;
 }
 AttachmentStream.Close();
 return SendOk;
 }

测试代码：

MemoryStream theMemStream = new MemoryStream();
 string file = @"C:\TestEmail\SKYPE11月黑咭生日會員.xls"; //C:\TestEmail\Top1000WorldBanks2014.pdf
 if (File.Exists(file))
 {
 //AttachmentStream = File.Open(file, FileMode.Open, FileAccess.Read);
 
 
 byte[] filebyte = MirosoftSmptHelper.ReadFile(file);
 
 theMemStream.Write(filebyte, 0, filebyte.Length);// = File.OpenRead(file); 
 theMemStream.Position = 0;
 
 //theMemStream.Close();
 
 // AttachmentStream = theMemStream;// BytesToStream(filebyte); //new MemoryStream(filebyte);// // BytesToStream(filebyte);// FileToStream(file);// 
 
 //AttachmentStream.CanTimeout =true;
 //AttachmentStream.ReadTimeout = 1000;
 //AttachmentStream.WriteTimeout = 1000;
 //AttachmentStream = BytesToStream(filebyte);
 
 //theMemStream.Close();
 }
 List<string> AttachmentFiles = new List<string>();
 AttachmentFiles.Add("馬拉松獎牌刻字.xlsx");
 AttachmentFiles.Add("进一步优化供给推动消费平稳增长2019.pdf");
 AttachmentFiles.Add("逃犯条例草案.pdf");
 AttachmentFiles.Add("复习卷14.doc");
 List<string> Tos = new List<string>();
 Tos.Add("geovindu@163.com");
 Tos.Add("geovindu@hotmail.com");
 Tos.Add("geovi@qq.com");
 
 //1.一人一附件
 //bool issend = MirosoftSmptHelper.SendEmaildu("geovindu@163.com", "中文文件名.net 4.0,geovindu 涂聚文塗聚文工團、", " 生命運浪漫滿屋geovindu江蘇黃河 上官放個屁，下官一台戲", true,"馬拉松獎牌刻字.xlsx");
 //2.一人多附件
 //bool issend = MirosoftSmptHelper.SendEmailduFiles("geovindu@163.com", "中文文件名.net 4.0,geovindu 涂聚文塗聚文工團、", " 生命運浪漫滿屋geovindu江蘇黃河 上官放個屁，下官一台戲", true, AttachmentFiles);
 //3.多人多附件
 bool issend = MirosoftSmptHelper.SendEmailsAndFiles(Tos, "中文文件名.net 4.0,geovindu 涂聚文塗聚文工團、", " 生命運浪漫滿屋geovindu江蘇黃河 上官放個屁，下官一台戲", true, AttachmentFiles);
 theMemStream.Close();
 if (issend)
 {
 MessageBox.Show("ok");
 }
 else
 {
 MessageBox.Show("no");
 }
 }

不忘初心，方得始终；初心易得，始终难守。

/// <summary>
 /// 多人多附件发送邮件
 /// 不考虑统计每封邮件发送状态（另外考虑完善代码）
 /// 2019-06-18 涂聚文 GeovinDu
 /// 2019-07-01
 /// </summary>
 /// <param name="Tos">多人接收邮件人</param>
 /// <param name="Subject">邮件标题</param>
 /// <param name="Msg">邮件内容</param>
 /// <param name="bodyHtml">是否網頁</param>
 /// <param name="AttachmentFiles">多附件--具体文件地址</param>
 /// <returns></returns>
 public static bool SendEmailsAndFiles(List<string> Tos, string Subject, string Msg, bool bodyHtml, List<string> AttachmentFiles)
 {
 MemoryStream AttachmentStream = new MemoryStream();
 bool SendOk = false;
 List<Attachment> all = new List<Attachment>();
 try
 {
 if (AttachmentStream != null && AttachmentFiles != null)
 {
 foreach (string filename in AttachmentFiles)
 {
 Attachment attachment = new Attachment(filename, MediaTypeNames.Application.Octet); // //AttachmentStream, filename
 ContentDisposition disposition = attachment.ContentDisposition;
 disposition.CreationDate = File.GetCreationTime(filename);
 disposition.ModificationDate = File.GetLastWriteTime(filename);
 disposition.ReadDate = File.GetLastAccessTime(filename);
 disposition.FileName = Path.GetFileName(filename);
 disposition.Size = new FileInfo(filename).Length; 
 disposition.DispositionType = DispositionTypeNames.Attachment;
 all.Add(attachment); //new Attachment(AttachmentStream, filename)
 }
 }
 if (Tos.Count > 0)
 {
 
 
 foreach (string To in Tos)
 {
 System.Net.Mail.MailMessage newMsg = new System.Net.Mail.MailMessage(System.Configuration.ConfigurationManager.AppSettings["mailCfg"], To, Subject, Msg);
 newMsg.BodyEncoding = System.Text.Encoding.UTF8;
 newMsg.HeadersEncoding = System.Text.Encoding.UTF8;
 newMsg.SubjectEncoding = System.Text.Encoding.UTF8;
 System.Net.Mail.SmtpClient smtpClient = new System.Net.Mail.SmtpClient();
 //smtpClient.Credentials = new NetworkCredential("geovindu@dusystem.com","888888");
 //smtpClient.Port = 25;
 //smtpClient.EnableSsl = false;
 if (AttachmentStream != null && AttachmentFiles != null)
 {
 foreach (Attachment attname in all)
 {
 
 
 newMsg.Attachments.Add(attname); //MediaTypeNames.Image.Jpeg) 
 
 }
 }
 newMsg.IsBodyHtml = bodyHtml; 
 smtpClient.Send(newMsg);
 SendOk = true;
 }
 }
 }
 catch (Exception ex)
 {
 ex.Message.ToString();
 AttachmentStream.Close();
 SendOk = false;
 }
 AttachmentStream.Close();
 return SendOk;
 }
 
 /// <summary>
 /// 多人多附件发送邮件
 /// 不考虑统计每封邮件发送状态（另外考虑完善代码）
 /// 2019-07-01 涂聚文 GeovinDu
 /// </summary>
 /// <param name="Tos">多人接收邮件人</param>
 /// <param name="Subject">邮件标题</param>
 /// <param name="Msg">邮件内容</param>
 /// <param name="bodyHtml">是否網頁</param>
 /// <param name="AttachmentFiles">多附件--根据运行程序目录地址</param>
 /// <returns></returns>
 public static bool SendEmailsAndLocalFiles(List<string> Tos, string Subject, string Msg, bool bodyHtml, List<string> AttachmentFiles)
 {
 MemoryStream AttachmentStream = new MemoryStream();
 bool SendOk = false;
 List<Attachment> all = new List<Attachment>();
 try
 {
 if (AttachmentStream != null && AttachmentFiles != null)
 {
 foreach (string filename in AttachmentFiles)
 {
 //具体的文件地址，用此法
 //Attachment attachment = new Attachment(filename, MediaTypeNames.Application.Octet); // //AttachmentStream, filename
 //ContentDisposition disposition = attachment.ContentDisposition;
 //disposition.CreationDate = File.GetCreationTime(filename);
 //disposition.ModificationDate = File.GetLastWriteTime(filename);
 //disposition.ReadDate = File.GetLastAccessTime(filename);
 //disposition.FileName = Path.GetFileName(filename);
 //disposition.Size = new FileInfo(filename).Length;
 //disposition.DispositionType = DispositionTypeNames.Attachment;
 all.Add(new Attachment(AttachmentStream, filename));//在运行程序的目录的文件没有问题，可执行。如是不是此语言件地址，附件无效
 }
 }
 if (Tos.Count > 0)
 {
 
 
 foreach (string To in Tos)
 {
 System.Net.Mail.MailMessage newMsg = new System.Net.Mail.MailMessage(System.Configuration.ConfigurationManager.AppSettings["mailCfg"], To, Subject, Msg);
 newMsg.BodyEncoding = System.Text.Encoding.UTF8;
 newMsg.HeadersEncoding = System.Text.Encoding.UTF8;
 newMsg.SubjectEncoding = System.Text.Encoding.UTF8;
 System.Net.Mail.SmtpClient smtpClient = new System.Net.Mail.SmtpClient();
 //smtpClient.Credentials = new NetworkCredential("geovindu@dusystem.com","888888");
 //smtpClient.Port = 25;
 //smtpClient.EnableSsl = false;
 if (AttachmentStream != null && AttachmentFiles != null)
 {
 foreach (Attachment attname in all)
 {
 newMsg.Attachments.Add(attname); //MediaTypeNames.Image.Jpeg) 
 
 }
 }
 newMsg.IsBodyHtml = bodyHtml;
 smtpClient.Send(newMsg);
 SendOk = true;
 }
 }
 }
 catch (Exception ex)
 {
 ex.Message.ToString();
 AttachmentStream.Close();
 SendOk = false;
 }
 AttachmentStream.Close();
 return SendOk;
 }

/// <summary>
 /// 20190702 多人邮件
 /// geovindu 涂聚文
 /// </summary>
 /// <param name="Mails"></param>
 /// <param name="Subject"></param>
 /// <param name="Msg"></param>
 /// <param name="bodyHtml"></param>
 /// <param name="AttachmentFiles"></param>
 /// <returns></returns>
 public static bool SendEmailsFiles(List<MailAddress> Mails, string Subject, string Msg, bool bodyHtml, List<string> AttachmentFiles)
 {
 MemoryStream AttachmentStream = new MemoryStream();
 bool SendOk = false;
 List<Attachment> all = new List<Attachment>();
 try
 {
 if (AttachmentStream != null && AttachmentFiles != null)
 {
 foreach (string filename in AttachmentFiles)
 {
 //具体的文件地址，用此法
 Attachment attachment = new Attachment(filename, MediaTypeNames.Application.Octet); // //AttachmentStream, filename
 ContentDisposition disposition = attachment.ContentDisposition;
 disposition.CreationDate = File.GetCreationTime(filename);
 disposition.ModificationDate = File.GetLastWriteTime(filename);
 disposition.ReadDate = File.GetLastAccessTime(filename);
 disposition.FileName = Path.GetFileName(filename);
 disposition.Size = new FileInfo(filename).Length;
 disposition.DispositionType = DispositionTypeNames.Attachment;
 all.Add(attachment);//在运行程序的目录的文件没有问题，可执行。如是不是此语言件地址，附件无效
 }
 }
 if (Mails.Count > 0)
 {
 
 int c = 1;
 foreach (MailAddress ToAddress in Mails)
 {
 
 MailAddress from=new MailAddress(System.Configuration.ConfigurationManager.AppSettings["mailCfg"],System.Configuration.ConfigurationManager.AppSettings["displayName"]);
 //from.DisplayName="";
 // from.Address=;
 System.Net.Mail.MailMessage newMsg = new System.Net.Mail.MailMessage();
 newMsg.From = from;
 newMsg.To.Add(ToAddress);
 newMsg.Subject = Subject;
 newMsg.Body = Msg;
 newMsg.BodyEncoding = System.Text.Encoding.UTF8;
 newMsg.HeadersEncoding = System.Text.Encoding.UTF8;
 newMsg.SubjectEncoding = System.Text.Encoding.UTF8;
 System.Net.Mail.SmtpClient smtpClient = new System.Net.Mail.SmtpClient();
 //smtpClient.Credentials = new NetworkCredential("geovindu@dusystem.com","888888");
 //smtpClient.Port = 25;
 //smtpClient.EnableSsl = false;
 if (AttachmentStream != null && AttachmentFiles != null)
 {
 foreach (Attachment attname in all)
 {
 newMsg.Attachments.Add(attname); //MediaTypeNames.Image.Jpeg) 
 }
 }
 newMsg.IsBodyHtml = bodyHtml;
 //smtpClient.Send(newMsg);
 smtpClient.SendCompleted += new SendCompletedEventHandler(SendCompletedCallback);
 string userState = "test message:"+c.ToString();
 smtpClient.SendAsync(newMsg, userState);
 SendOk = true;
 c++;
 }
 
 }
 }
 catch (Exception ex)
 {
 ex.Message.ToString();
 AttachmentStream.Close();
 SendOk = false;
 }
 AttachmentStream.Close();
 return SendOk;
 }
 /// <summary>
 /// 一人多附件
 /// </summary>
 /// <param name="Mails"></param>
 /// <param name="Subject"></param>
 /// <param name="Msg"></param>
 /// <param name="bodyHtml"></param>
 /// <param name="AttachmentFiles"></param>
 /// <returns></returns>
 public static bool SendEmailFiles(MailAddress Mails, string Subject, string Msg, bool bodyHtml, List<string> AttachmentFiles)
 {
 MemoryStream AttachmentStream = new MemoryStream();
 bool SendOk = false;
 List<Attachment> all = new List<Attachment>();
 try
 {
 if (AttachmentStream != null && AttachmentFiles != null)
 {
 foreach (string filename in AttachmentFiles)
 {
 //具体的文件地址，用此法
 Attachment attachment = new Attachment(filename, MediaTypeNames.Application.Octet); // //AttachmentStream, filename
 ContentDisposition disposition = attachment.ContentDisposition;
 disposition.CreationDate = File.GetCreationTime(filename);
 disposition.ModificationDate = File.GetLastWriteTime(filename);
 disposition.ReadDate = File.GetLastAccessTime(filename);
 disposition.FileName = Path.GetFileName(filename);
 disposition.Size = new FileInfo(filename).Length;
 disposition.DispositionType = DispositionTypeNames.Attachment;
 all.Add(attachment);//在运行程序的目录的文件没有问题，可执行。如是不是此语言件地址，附件无效
 }
 } 
 
 
 MailAddress from = new MailAddress(System.Configuration.ConfigurationManager.AppSettings["mailCfg"], System.Configuration.ConfigurationManager.AppSettings["displayName"]);
 //from.DisplayName="";
 // from.Address=;
 System.Net.Mail.MailMessage newMsg = new System.Net.Mail.MailMessage();
 newMsg.From = from;
 newMsg.To.Add(Mails);
 newMsg.Subject = Subject;
 newMsg.Body = Msg;
 newMsg.BodyEncoding = System.Text.Encoding.UTF8;
 newMsg.HeadersEncoding = System.Text.Encoding.UTF8;
 newMsg.SubjectEncoding = System.Text.Encoding.UTF8;
 System.Net.Mail.SmtpClient smtpClient = new System.Net.Mail.SmtpClient();
 //smtpClient.Credentials = new NetworkCredential("geovindu@dusystem.com","888888");
 //smtpClient.Port = 25;
 //smtpClient.EnableSsl = false;
 if (AttachmentStream != null && AttachmentFiles != null)
 {
 foreach (Attachment attname in all)
 {
 newMsg.Attachments.Add(attname); //MediaTypeNames.Image.Jpeg) 
 }
 }
 newMsg.IsBodyHtml = bodyHtml;
 //smtpClient.Send(newMsg);
 smtpClient.SendCompleted += new SendCompletedEventHandler(SendCompletedCallback);
 string userState = "test message:发送中";
 smtpClient.SendAsync(newMsg, userState);
 SendOk = true; 
 
 
 }
 catch (Exception ex)
 {
 ex.Message.ToString();
 AttachmentStream.Close();
 SendOk = false;
 }
 AttachmentStream.Close();
 return SendOk;
 }

测试

List<MailAddress> mails = new List<MailAddress>();
 MailAddress address = null;
 address = new MailAddress("geovindu@163.com", "涂聚文", Encoding.UTF8); 
 mails.Add(address);
 address = new MailAddress("geovindu@hotmail.com", "塗聚文", Encoding.UTF8);
 mails.Add(address);
 address = new MailAddress("463588883@qq.com", "捷為工作室", Encoding.UTF8);
 mails.Add(address);
 string strMessage = string.Empty;
 string subject = string.Empty;
 
 subject=txtSubject.Text.Trim();
 strMessage = htmlEditUserControl1.HtmlEditControl.DocumentText;
 
 //1.一人一附件
 //bool issend = MirosoftSmptHelper.SendEmaildu("geovindu@163.com", "中文文件名.net 4.0,geovindu 涂聚文塗聚文工團、", " 生命運浪漫滿屋geovindu江蘇黃河 上官放個屁，下官一台戲", true,"馬拉松獎牌刻字.xlsx");
 //2.一人多附件
 //bool issend = MirosoftSmptHelper.SendEmailduFiles("geovindu@163.com", "中文文件名.net 4.0,geovindu 涂聚文塗聚文工團、", " 生命運浪漫滿屋geovindu江蘇黃河 上官放個屁，下官一台戲", true, AttachmentFiles);
 //3.多人多附件
 //bool issend = MirosoftSmptHelper.SendEmailsAndFiles(Tos, subject, strMessage, true, AttachmentFiles);
 bool issend = MirosoftSmptHelper.SendEmailsFiles(mails, subject, strMessage, true, AttachmentFiles);

转载于:https://www.cnblogs.com/geovindu/p/11045584.html