def initialize(addr, port = nil, isapop = false)
      @address = addr
      @ssl_params = POP3.ssl_params
      @port = port
      @apop = isapop

      @command = nil
      @socket = nil
      @started = false
      @open_timeout = 30
      @read_timeout = 60
      @debug_output = nil

      @mails = nil
      @n_mails = nil
      @n_bytes = nil
    end
Creates a new POP3 object.

+address+ is the hostname or ip address of your POP3 server.

The optional +port+ is the port to connect to.

The optional +isapop+ specifies whether this connection is going
to use APOP authentication; it defaults to +false+.

This method does *not* open the TCP connection.