A "Notice Left" usually means a delivery notice card is left due to some reasons your package cannot be tracked.
Possible reasons why there is a "Notice Left".
1. The package size is bigger than the compartment of the recipient's mail box. Therefore, it is usually left in the post office waiting for the receiver to pick up.
2. There is no room to put any other packages in the community mailbox.
3. The person who are supposed to receive this package are not available. And the sender does not agree with other delivery options, like a safe drop.
4. You are absent from home and there is no appropriate place, a safe place for the driver to leave your product when the delivery was made.
5. The sender of your item has requested the "card for pickup" option, then the item must be picked up at a post office.
Want to know how to pick up packages at the post office? Click this article.