- Incorrect Address: The most frequent cause.
- Addressee Moved: The person no longer lives at that address.
- No Such Mailbox: The address might be valid, but there's no mailbox for it.
- Refused: The recipient actively declined to accept the mail.
- Undeliverable as Addressed: The address is incomplete or unclear.
- Address Errors: This is like trying to find a friend's house without the right street number or zip code. Even a small typo can send your mail on a wild goose chase.
- Recipient Relocation: People move, and sometimes they forget to update their address with everyone. If they haven't filed a change of address with the post office, their mail will eventually be returned.
- Delivery Obstacles: Sometimes, the physical location has issues, like a damaged mailbox or a property that's inaccessible.
| Reason | Meaning |
|---|---|
| No Such Address | The address doesn't exist. |
| Moved, Left No Address | The person moved and didn't leave forwarding information. |
| Insufficient Postage | Not enough money was paid for the postage. |