while true do
  local senderId, message, protocol = rednet.receive()
    if message == "getmail" then
	  local senderId, message, protocol = rednet.receive()
	  file = fs.open(message, "r")
      text = file.readAll()
      file.close()
	  rednet.send(senderId, text)
	else
	  local senderId, message2, protocol = rednet.receive()
	  file = fs.open(message, "a")
	  file.writeLine(message2)
	  file.close()
	end
end