If you're not home and the neighbor notices something suspicious happening at your house, they could call the cops/call you, or they could just pretend they didn't see it because FU. If your mailbox is on the other side of the street in someone else's lawn, they could weed whack carefully around it or they could """accidentally""" damage the post every time. They could pick up their dog's shit or they could send their dog over to use your yard. While all of those negative outcomes could be solved with security cameras and at worst a trip to small claims court, it's still a hassle. Just depends on what's worth more to you.