public void CreateNewClient(MailBoxDto mailBox)
        {
            _logger.LogDebug("Adding client for Mail Box {id} ...", mailBox.Id);
            var client = new MailBoxClient(_clientLogger, mailBox, _mapper);

            AddClient(client);
        }
 private void AddClient(MailBoxClient client)
 {
     _clients.Add(client.Identifier, client);
     _tasks.Add(client.Identifier, client.Run());
 }