: new(host, port = 143, usessl = false, certs = nil, verify = false)
      Creates a new Net::IMAP object and connects it to the specified
      port on the named host.  If usessl is true, then an attempt will
      be made to use SSL (now TLS) to connect to the server.  For this
      to work OpenSSLimap.rb"/[OSSL] and the Ruby OpenSSLimap.rb"/[RSSL]
      extension need to be installed.  The certs parameter indicates
      the path or file containing the CA cert of the server, and the
      verify parameter is for the OpenSSL verification callback.

