Is this legal?

I live in PA. A friend of mine is a handyman and looks for small home improvement jobs. He made a flyer listing his contact number and the projects that he can do. He asked me to help him distribute the copies of his flyer in my neighborhood by putting the flyers in the neighbors’ mailboxes or door handles. I wonder if this is legal since I live in a “no soliciting” neighborhood. Also, if a neighborhood allows soliciting, will he get into trouble for putting flyers into people’s mailbox by himself and not via the postal service? Thanks in advance for any help.