Businesses need shipping and logistics on a daily basis. However, bad guys find ways to screw people by manipulating bulk emails to pretend to be UPS, US Postal Service, FedEx or other delivery services.
Here is another good example
Although it says USPS on top, real email address is not the one from USPS. The invoice link also is fake, if you point your mouse over it, you will see something else which is not USPS.
In the event you receive an email similar to this with the same characteristics, it most likely is a fake email trying to pretend to be USPS. Do not open the link since it can steal your information.