partial class EmailService : ServiceBase
{
    private static MessageQueue msgQ = null;
    private static object lockObject = new object();
    private SmtpClient objSmtpClient;
    private MailMessage objMailMsg;
    private string mailFrom="";
    EmailMessage msg;

   Log Log;
    public EmailService()
    {
        InitializeComponent();
        Log l= new Log();
    }

    public void OnStart()
   // protected override void OnStart(string[] args)
    {
        string queuePath = ConfigurationManager.AppSettings["mqPath"];
        mailFrom = ConfigurationManager.AppSettings["notificationemail"];
        string SMTPSSLConfig = ConfigurationManager.AppSettings["smtpclientssl"];
        if (string.IsNullOrEmpty(queuePath))
        {
            throw new Exception("Message queue path not defined in app.config.");
        }
        if (string.IsNullOrEmpty(mailFrom))
        {
            throw new Exception("Sender email used to send  notifications is not defined in app.config.");
        }
        if (string.IsNullOrEmpty(SMTPSSLConfig))
        {
            throw new Exception("SMTP SSL config not defined in app.config.");
        }
        objSmtpClient = new SmtpClient();
        objSmtpClient.EnableSsl = Convert.ToBoolean(SMTPSSLConfig);

        //QueueService.InsureQueueExists(queuePath);
        msgQ = new MessageQueue(queuePath);
        msgQ.Formatter = new BinaryMessageFormatter();
        msgQ.MessageReadPropertyFilter.SetAll();
        msgQ.ReceiveCompleted += new ReceiveCompletedEventHandler(msgQ_ReceiveCompleted);
        msgQ.BeginReceive();
        try
        {
            if (!MessageQueue.Exists(queuePath))
            {
                MessageQueue.Create(queuePath);
                Log.WriteMessageQueueInitialParamsLog(System.DateTime.Now.ToString()+" :Message queue successfully created at following location:"+queuePath);
            }
            else
            {
                Log.WriteMessageQueueInitialParamsLog(System.DateTime.Now.ToString() + ": Message Queue Path: " + msgQ.Path);
            }
        }
        catch (Exception ex)
        {
            Log.WriteCommonLog(System.DateTime.Now.ToString() + " :Error checking message queue existence:\n"+GetExceptionMessageString(ex));
        }

        //eventLog1.WriteEntry(System.DateTime.Now.ToString()+" :EmailService started successfully." );
        Log.WriteMessageQueueInitialParamsLog(System.DateTime.Now.ToString()+" :Message queue started successfully.");

    }

    private void msgQ_ReceiveCompleted(object sender, ReceiveCompletedEventArgs e)
    {
        try
        {
            lock (lockObject)
            {
                msg = (EmailMessage)e.Message.Body;
                Log.WriteMessageQueueLog(System.DateTime.Now.ToString() + " :Message retrieved from message Queue: From:" + msg.From + "  To:" + msg.To + "  Subject:" + msg.Subject);
                SendEmail(msg);
            }

            // Listen for the next message.
            msgQ.BeginReceive();
        }
        catch(Exception ex)
        {
            Log.WriteCommonLog(GetExceptionMessageString(ex));
        }
    }
    protected override void OnStop()
    {
        msgQ.Close();
        //eventLog1.WriteEntry(System.DateTime.Now.ToString()+" :EmailService stopped.");
        Log.WriteMessageQueueInitialParamsLog(System.DateTime.Now.ToString()+" :Message queue stopped successfully.");
    }
    private void SendEmail(EmailMessage objMail)
    {
        try
        {
            if(string.IsNullOrEmpty(mailFrom) || string.IsNullOrEmpty(objMail.To))
                throw new Exception("Either sender email address is null or receiver email address is null.");

            objMailMsg = new MailMessage(new MailAddress(mailFrom), new MailAddress(objMail.To));
            objMailMsg.ReplyTo = new MailAddress(mailFrom);
            objMailMsg.IsBodyHtml = true;
            objMailMsg.Subject = objMail.Subject;
            objMailMsg.Body = objMail.Message;
            objSmtpClient.Send(objMailMsg);
            Log.WriteEmailLog("Email Sent:  DateTime:" + System.DateTime.Now.ToString() + "  To:" + objMail.To + "  From:" + mailFrom + "  Subject:" + objMail.Subject);
            System.Threading.Thread.Sleep(1000);
        }
        catch (System.Net.Mail.SmtpException se)
        {
            if (se.StatusCode == SmtpStatusCode.MailboxBusy)
            {
                new QueueService().QueueMessage(objMail);
                Log.WriteCommonLog("SMTP Exception:" + GetExceptionMessageString(se));
            }
            else
            {
                Log.WriteCommonLog("SMTP Exception:" + GetExceptionMessageString(se));
            }
        }
        catch (System.Net.WebException we)
        {
            if ((we.Status == System.Net.WebExceptionStatus.ConnectFailure) || (we.Status == System.Net.WebExceptionStatus.ConnectionClosed) || (we.Status == System.Net.WebExceptionStatus.ReceiveFailure) || (we.Status == System.Net.WebExceptionStatus.Timeout) || (we.Status == System.Net.WebExceptionStatus.NameResolutionFailure))
            {
                new QueueService().QueueMessage(objMail);
                Log.WriteCommonLog("Web Exception:" + GetExceptionMessageString(we));
            }
            else
            {
                Log.WriteCommonLog("Web Exception:" + GetExceptionMessageString(we));
            }
        }
        catch (Exception ex)
        {
            Log.WriteCommonLog("Web Exception:" + GetExceptionMessageString(ex));
        }

    }
    private string GetExceptionMessageString(Exception exc)
    {
        return "\nException thrown by EmailService\n" + System.DateTime.Now.ToString() + "\nInner Exception:" + exc.InnerException + "\nException Message:" + exc.Message + "\nSource:" + exc.Source + "\nStack Trace:" + exc.StackTrace;
    }
}