Resident: Hi, I received these two letters for my neighbors in my mailbox.
Resident: Can you fix this?
Me: I can't really do anything about it. You need to talk to the US Postal Service, they're the ones who deliver the mail.
Resident: But this isn't my address, it makes me wonder if my mail is going to other people.
Me: We in the office have NOTHING to do with mail delivery, so I really can't say.
Resident: It's ridiculous! **shows me the envelopes with the incorrect addresses**
Me: Yes, but again, you have to take this up with your mailmen or the local post office.
Resident: Can you tell [my boss]?
Me: He can't do anything about it; we have no control over the USPS. YOU have to talk to THEM.
Resident: But I have a baby, and no time-
Me: But we have nothing to do with the postal service, so we really can't do anything for you.
Resident: Tell [my boss]!
Me: ...I can tell him, but he can't do anything.
Resident: Thanks, bye! **leaves the mail of her neighbors with me**
It's like thinking the traffic lights at an intersection are changing too quickly to allow a smooth flow of traffic, so you go into the gas station situated at the corner and complain to them. They might agree with you and yes, they work with cars but ultimately they have nothing to do with the problem you're experiencing.
I toss the envelopes into our "outgoing mail" box and wonder why she didn't just drop the letters off at her neighbors' houses. I also kinda think that if she has the time to come down here to the office and complain, she can get on the phone with the local post office branch and talk to someone who can actually do something about the situation.