使用C#编写简单的图形化的可发送附件的邮件客户端程序

SmtpClient SmtpClient = null; //设置SMTP协议MailAddress MailAddress_from = null; //设置发信人地址 当然还需要密码MailAddress MailAddress_to = null; //设置收信人地址 不需要密码MailMessage MailMessage_Mai = null;FileStream FileStream_my = null; //附件文件流

#region 设置Ｓmtp服务器信息/// <summary>/// 设置Ｓmtp服务器信息/// </summary>/// <param name="ServerName">SMTP服务名</param>/// <param name="Port">端口号</param>private void setSmtpClient(string ServerHost, int Port){SmtpClient = new SmtpClient();SmtpClient.Host = ServerHost;//指定SMTP服务名 例如QQ邮箱为 smtp.qq.com 新浪cn邮箱为 smtp.sina.cn等SmtpClient.Port = Port; //指定端口号SmtpClient.Timeout = 0; //超时时间}#endregion

#region 验证发件人信息/// <summary>/// 验证发件人信息/// </summary>/// <param name="MailAddress">发件邮箱地址</param>/// <param name="MailPwd">邮箱密码</param>private void setAddressform(string MailAddress, string MailPwd){//创建服务器认证NetworkCredential NetworkCredential_my = new NetworkCredential(MailAddress, MailPwd);//实例化发件人地址MailAddress_from = new System.Net.Mail.MailAddress(MailAddress, textBoxX4.Text);//指定发件人信息 包括邮箱地址和邮箱密码SmtpClient.Credentials = new System.Net.NetworkCredential(MailAddress_from.Address, MailPwd);;}#endregion

#region 检测附件大小private bool Attachment_MaiInit(string path){try{FileStream_my = new FileStream(path, FileMode.Open);string name = FileStream_my.Name;int size = (int)(FileStream_my.Length / 1024/1024);FileStream_my.Close();//控制文件大小不大于10Ｍif (size > 10){MessageBox.Show("文件长度不能大于10M！你选择的文件大小为"+ size.ToString()+"M","警告",MessageBoxButtons.OK,MessageBoxIcon.Warning);return false;}return true;}catch (IOException E){MessageBox.Show(E.Message);return false;}}#endregion

 private void btnSend_Click(object sender, EventArgs e){//检测附件大小 发件必需小于10M 否则返回 不会执行以下代码if (txt_Path.Text != ""){if (!Attachment_MaiInit(txt_Path.Text.Trim())){return;}}if (txt_SmtpServer.Text == ""){MessageBox.Show("请输入SMTP服务器名！", "提示", MessageBoxButtons.OK, MessageBoxIcon.Warning);return;}if (textBoxX2.Text == ""){MessageBox.Show("请输入发件人邮箱地址！", "提示", MessageBoxButtons.OK, MessageBoxIcon.Warning);return;}if (txtformPwd.Text == ""){MessageBox.Show("请输入发件人邮箱密码！", "提示", MessageBoxButtons.OK, MessageBoxIcon.Warning);return;}if (dataGridViewX1.Rows.Count == 0){MessageBox.Show("请添加收件人！", "提示", MessageBoxButtons.OK, MessageBoxIcon.Warning);return;}if (MessageBox.Show("您确定要发送当前邮件吗？", "询问", MessageBoxButtons.OKCancel, MessageBoxIcon.Question) == DialogResult.OK){try{//初始化Ｓmtp服务器信息setSmtpClient("smtp." + txt_SmtpServer.Text.Trim() + comboBoxEx3.Text, Convert.ToInt32(numericUpDown1.Value));}catch (Exception Ex){MessageBox.Show("邮件发送失败,请确定SMTP服务名是否正确！" + "/n" + "技术信息:/n" + Ex.Message, "错误", MessageBoxButtons.OK, MessageBoxIcon.Error);return;}try{//验证发件邮箱地址和密码setAddressform(textBoxX2.Text.Trim() + comboBoxEx2.Text, txtformPwd.Text.Trim());}catch (Exception Ex){MessageBox.Show("邮件发送失败,请确定发件邮箱地址和密码的正确性！" + "/n" + "技术信息:/n" + Ex.Message, "错误", MessageBoxButtons.OK, MessageBoxIcon.Error);return;}//清空历史发送信息 以防发送时收件人收到的错误信息(收件人列表会不断重复)MailMessage_Mai.To.Clear();//添加收件人邮箱地址foreach (DataGridViewRow row in dataGridViewX1.Rows){MailAddress_to = new MailAddress(row.Cells["Column1"].Value.ToString());MailMessage_Mai.To.Add(MailAddress_to);}MessageBox.Show("收件人：" + dataGridViewX1.Rows.Count.ToString() + " 个");//发件人邮箱MailMessage_Mai.From = MailAddress_from;//邮件主题MailMessage_Mai.Subject = txttitle.Text;MailMessage_Mai.SubjectEncoding = System.Text.Encoding.UTF8;//邮件正文MailMessage_Mai.Body = Rtb_Message.Text;MailMessage_Mai.BodyEncoding = System.Text.Encoding.UTF8;//清空历史附件 以防附件重复发送MailMessage_Mai.Attachments.Clear();//添加附件MailMessage_Mai.Attachments.Add(new Attachment(txt_Path.Text.Trim(), MediaTypeNames.Application.Octet));//注册邮件发送完毕后的处理事件SmtpClient.SendCompleted += new SendCompletedEventHandler(SendCompletedCallback);//开始发送邮件SmtpClient.SendAsync(MailMessage_Mai, "000000000");}}

#region 发送邮件后所处理的函数private static void SendCompletedCallback(object sender, AsyncCompletedEventArgs e){try{if (e.Cancelled){MessageBox.Show("发送已取消！");}if (e.Error != null){ MessageBox.Show("邮件发送失败！" + "/n" + "技术信息:/n" + e.ToString(), "错误", MessageBoxButtons.OK, MessageBoxIcon.Error); }else{MessageBox.Show("邮件成功发出!", "恭喜!", MessageBoxButtons.OK, MessageBoxIcon.Information);}}catch (Exception Ex){MessageBox.Show("邮件发送失败！" + "/n" + "技术信息:/n" + Ex.Message, "错误", MessageBoxButtons.OK, MessageBoxIcon.Error);} }#endregion