do_start

# File lib/net/pop.rb, line 533
    def do_start(account, password)
      s = timeout(@open_timeout) { TCPSocket.open(@address, port) }
      if use_ssl?
        raise 'openssl library not installed' unless defined?(OpenSSL)
        context = OpenSSL::SSL::SSLContext.new
        context.set_params(@ssl_params)
        s = OpenSSL::SSL::SSLSocket.new(s, context)
        s.sync_close = true
        s.connect
        if context.verify_mode != OpenSSL::SSL::VERIFY_NONE
          s.post_connection_check(@address)
        end
      end
      @socket = InternetMessageIO.new(s)
      logging "POP session started: #{@address}:#{@port} (#{@apop ? 'APOP' : 'POP'})"
      @socket.read_timeout = @read_timeout
      @socket.debug_output = @debug_output
      on_connect
      @command = POP3Command.new(@socket)
      if apop?
        @command.apop account, password
      else
        @command.auth account, password
      end
      @started = true
    ensure
      # Authentication failed, clean up connection.
      unless @started
        s.close if s and not s.closed?
        @socket = nil
        @command = nil
      end
    end