[header] How to send a letter without your parents knowing [title] Know when your mailman comes. [step] Find out at what time your mailman comes; they usually come at a certain time range, so watch for a few days and keep track of the time. [substeps] If your mailman comes when you are at school, try it on a saturday. 
On saturdays your mailman may come at a different time from when they do on weekdays. [title] Place the letter in at the right time.