.NET接收邮件下载邮件附件——openpop.net

使用OpenPop.Net接收邮件很方便，下面是接收下载邮件附件的代码

OpenPop.Net下载地址 https://sourceforge.net/projects/hpop/

    public class EmailHelper
    {
        private string accout; //邮箱账户
        private string pass;//邮箱密码
        private string popServer; //pop服务地址(阿里云：pop3.mxhichina.com)
        private int popPort; //pop服务端口号（110）
        private bool isUseSSL;

        public EmailHelper(string _accout, string _pass, string _popServer, int _popPort, bool _isUseSSL)
        {
            this.accout = _accout;
            this.pass = _pass;
            this.popServer = _popServer;
            this.popPort = _popPort;
            this.isUseSSL = _isUseSSL;
        }

        #region 验证邮箱是否登录成功
        public bool ValidateAccount(ref string error)
        {
            Pop3Client client = new Pop3Client();
            try
            {
                client.Connect(popServer, popPort, isUseSSL);
                client.Authenticate(accout, pass);
            }
            catch (InvalidLoginException ex)
            {
                error = "邮箱登录失败！";
                return false;
            }
            catch (InvalidUseException ex)
            {
                error = "邮箱登录失败！";
                return false;
            }
            catch (PopServerNotFoundException ex)
            {
                error = "服务器没有找到！";
                return false;
            }
            catch (PopServerException ex)
            {
                error = "请在邮箱开通POP3/SMTP！";
                return false;
            }
            catch (Exception ex)
            {
                error = "连接出现异常";
                return false;
            }
            finally
            {
                client.Disconnect();
            }
            return true;
        }
        #endregion


        # region 下载邮件附件
        /// <summary>
        /// 下载邮件附件
        /// </summary>
        public void DownAttachments(string path)
        {
            using (Pop3Client client = new Pop3Client())
            {
                if (client.Connected)
                {
                    client.Disconnect();
                }
                client.Connect(popServer, popPort, isUseSSL);
                client.Authenticate(accout, pass, AuthenticationMethod.UsernameAndPassword);
                int messageCount = client.GetMessageCount();
                StringBuilder strBuilder = new StringBuilder();
                int count = Convert.ToInt32(SqlHelper.ExecuteScalar("SELECT COUNT(1) FROM EmailList"));
                int i = 1;
                for (i = count + 1; i <= messageCount; i++)
                {
                    Message message = client.GetMessage(i);
                    string senders = message.Headers.From.DisplayName;
                    string from = message.Headers.From.Address;
                    string subject = message.Headers.Subject;
                    DateTime Datesent = message.Headers.DateSent;


                    List<MessagePart> messageParts = message.FindAllAttachments();
                    foreach (var item in messageParts)
                    {
                        if (item.IsAttachment)
                        {
                            if (!File.Exists(path + item.FileName))
                            {
                                if (item.FileName.Contains(".zip") || item.FileName.Contains(".rar"))
                                    File.WriteAllBytes(path + item.FileName, item.Body);
                            }
                        }
                    }

                    strBuilder.Append("INSERT INTO [dbo].[EmailList]([Title],[FromAdd],[Time],[isFlag]) VALUES (");
                    strBuilder.Append("'" + subject + "'," + "'" + from + "'," + "'" + Datesent.ToString("yyyy-MM-dd HH:mm:ss") + "'," + 1);
                    strBuilder.Append(")");
                    SqlHelper.ExecuteNonQuery(strBuilder.ToString());
                    strBuilder.Clear();

                }
            }
        }
        #endregion


        #region 下载邮件附件
        /// <summary>
        /// 下载邮件附件
        /// </summary>
        public void DownAttachmentsById(string path, int messageId)
        {
            using (Pop3Client client = new Pop3Client())
            {
                if (client.Connected)
                {
                    client.Disconnect();
                }
                client.Connect(popServer, popPort, isUseSSL);
                client.Authenticate(accout, pass, AuthenticationMethod.UsernameAndPassword);
                Message message = client.GetMessage(messageId);
                string senders = message.Headers.From.DisplayName;
                string from = message.Headers.From.Address;
                string subject = message.Headers.Subject;
                DateTime Datesent = message.Headers.DateSent;


                List<MessagePart> messageParts = message.FindAllAttachments();
                foreach (var item in messageParts)
                {
                    if (item.IsAttachment)
                    {
                        if (!File.Exists(path + item.FileName))
                        {
                            if (item.FileName.Contains(".zip") || item.FileName.Contains(".rar"))
                                File.WriteAllBytes(path + item.FileName, item.Body);
                        }
                    }
                }

                MessagePart nomessageParts = message.FindFirstHtmlVersion();
                string html = nomessageParts.GetBodyAsText();
                Regex reg = new Regex(@"(?is)<a[^>]*?href=(['""]?)(?<url>[^'""s>]+)1[^>]*>(?<text>(?:(?!</?a).)*)</a>");
                MatchCollection mc = reg.Matches(html);
                string url = string.Empty;

                url = mc[0].Groups["url"].Value;
                HttpWebRequest req = (HttpWebRequest)HttpWebRequest.Create(url);
                req.Method = "GET";
                using (WebResponse res = req.GetResponse())
                {
                    string reader = new StreamReader(res.GetResponseStream(), Encoding.GetEncoding("utf-8")).ReadToEnd();
                    MatchCollection ms = reg.Matches(reader);
                    url = ms[0].Groups["url"].Value;
                }
            }
        }
        #endregion

        #region
        /// <summary>
        /// 获取邮件数量
        /// </summary>
        /// <returns></returns>
        public int GetEmailCount()
        {
            int messageCount = 0;
            using (Pop3Client client = new Pop3Client())
            {
                if (client.Connected)
                {
                    client.Disconnect();
                }
                client.Connect(popServer, popPort, isUseSSL);
                client.Authenticate(accout, pass, AuthenticationMethod.UsernameAndPassword);
                messageCount = client.GetMessageCount();
            }

            return messageCount;
        }
        #endregion


    }