Does anyone know if the USPS uses scanners to read the addresses on the mail?

I've received mail for different addresses before. One time I put the letter back in the mail and received it again. I did the same thing and received it again. I wrote on it that it was going in the trash if I received it again and it didn't come back. I've crossed out addresses and rewrote them, but I believe you also have to cross out the bar code under the address or it will come back to you. That leads me to believe a person isn't reading these addresses. Sometimes the sender is putting a loop in the name which partially covers the address line and someone/something is reading that as a 0 in the street name. I cross all that out and rewrite the address clearly. If it still comes to me it goes in the trash, but I don't recall having anything that I've rewritten and crossed out the bar code come back to me.

I do receive mail with my address and different name that I just throw away.