From the USPS Office of Inspector General:
In today’s world of package tracking and interconnectivity, an email from the U.S. Postal Service or even our Inspector General regarding mail delivery might seem legitimate.
That’s what the scammers want you to think.
Unfortunately, some postal customers are getting bogus emails purporting to be from the Postal Service about an attempted or intercepted package delivery or online postage charges. These emails contain a link or attachment that, when opened, installs a malicious virus that can steal personal information from your personal computer.
If you receive a suspicious-looking email, do not click on the link or open the attachment. Like most viruses sent by email, doing so will activate a virus that can steal information — such as your user name, password, and financial account information. Simply delete the message without taking any further action.
And if you do receive an email that appears to be from the Postal Service and there is something that appears to be suspicious about it, you are welcome to report it to our Hotline.