void OnDoWork(object sender, DoWorkEventArgs e)
{
    while (_messages.Count > 0)
    {
        TcpClient client = new TcpClient();
        try
        {
            client.Connect(IPAddress.Parse(_activeHost.IP), _activeHost.Port);

            string message = _messages.Dequeue();

            byte[] buffer = Encoding.Unicode.GetBytes(message);

            client.Client.Send(buffer);

            Log(new MessageEventArgs(message, _messages.Count, MessageStatus.Success, null));
        }
        catch (SocketException ex)
        {
            _hasFailures = true;
            string[] messages = _messages.ToArray();
            Log(new MessageEventArgs(null, _messages.Count, MessageStatus.Failure, ex.Message));

            _messages.Clear();
            //save array to file
            StringBuilder allMessages = new StringBuilder();
            foreach (string message in messages)
            {
                allMessages.Append(message + Environment.NewLine);
            }
            File.AppendAllText(_filepath, allMessages.ToString(), Encoding.UTF8);
            //failover
            _activeHost = FindHost();
        }
        finally
        {
            if (client.Connected)
            {
                client.Client.Shutdown(SocketShutdown.Both);
                client.Client.Disconnect(false);
            }
        }
    }
    _backgroundWorker = null;
}