前段时间做了个关于邮件的东西，记录一下如何解析和保存eml文件的。    

    /// <summary>
        /// 解析eml
        /// </summary>
        private void AnalyzeEmlFile()
        {
        //    CDO.Message oMsg = new CDO.Message();
        //    ADODB.Stream stm = null;
        //    //读取EML文件到CDO.MESSAGE
        //    try
        //    {
        //        stm = new ADODB.Stream();
        //        stm.Open(System.Reflection.Missing.Value,
        //        ADODB.ConnectModeEnum.adModeUnknown,
        //        ADODB.StreamOpenOptionsEnum.adOpenStreamUnspecified,
        //        "", "");
        //        stm.Type = ADODB.StreamTypeEnum.adTypeBinary;//二进制方式读入
        //        stm.LoadFromFile(emlpath); //将EML读入数据流
        //        oMsg.DataSource.OpenObject(stm, "_stream"); //将EML数据流载入到CDO.Message

        //    }
        //    catch (IOException ex)
        //    {
        //        using (StreamWriter writer = new StreamWriter(GlobalConstants.MailLogPath, true))
        //        {
        //            writer.WriteLine("解析eml文件出现异常" + DateTime.Now + "/n" + ex.Message);
        //            writer.Close();
        //        }
        //    }
        //    finally
        //    {
        //        stm.Close();
        //    }
        }

        /// <summary>
        /// 将mailmessage保存为.eml文件
        /// </summary>
        /// <param name="msg">待保存的具有内容的MailMessage</param>
        /// <param name="emlFileAbsolutePath">保存后的eml文件的路径</param>
        static void SaveToEml(MailMessage msg, string emlFileAbsolutePath)
        {
            //const BindingFlags flags = BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.FlattenHierarchy;
            //using (MemoryStream ms = new MemoryStream())
            //{
            //    Assembly assembly = typeof(System.Net.Mail.SmtpClient).Assembly;
            //    Type tMailWriter = assembly.GetType("System.Net.Mail.MailWriter");
            //    object mailWriter = Activator.CreateInstance(tMailWriter, flags, null, new object[] { ms }, CultureInfo.InvariantCulture);
            //    msg.GetType().GetMethod("Send", flags).Invoke(msg, new object[] { mailWriter, true });
            //    File.WriteAllText(emlFileAbsolutePath, System.Text.Encoding.Default.GetString(ms.ToArray()), System.Text.Encoding.Default);
            //}
        }

第二种方法保存.eml(缺陷是保存的文件名为随机的guid )

 //smtpClient.EnableSsl = false;
                        // smtpClient.PickupDirectoryLocation = mailPath;//要保存的路径
                        //smtpClient.DeliveryMethod = SmtpDeliveryMethod.SpecifiedPickupDirectory;