Is it a federal offense to put flyers in private mailboxes?

im putting a babysitting flyer out but dont want to put it the neighborhood. I wish i could put in mailboxes that have children living surrounded by the houses. i saw on the interenet it is a federal offense. But i am not sure....could i be sued??
Only the US postal service can place items inside a mailbox, time of year.

But you can tape the flyer to the outside, they don't own that.
Yes, I'm a rural carrier within my hometown so I would know. We get safety talks at work adjectives the time about this sort of thing. If I was you I would recommend basically putting them between the door or sticking them where they are easily found.

Do Not Put them in the Mail BOX!
it is. It's interfering with the US Postal System, which is a federal offense.
Yes, it is against the law. Only a US Postal carrier can put anything into a mailbox.

You enjoy to stick them in the door or something else like that.
It violates the DMM and constitutes a federal offense to put any object in the mailbox that does not carry valid postage.
I would also like to say that I hate when citizens put things on my door or in any very visible location outside my door as this merely tips of potential burglars to the reality that I am not home.
I don't mind getting flyers since they sometimes have good deals, but I greatly prefer when they are slipped lower than my door or concealed on the inside of my screen door so nobody can tell that I am not at home.