Suggest Law: If a company's electronic notification to you is so phishy that a "reasonable man" would have obvious cause to doubt its legitimacy, then all financial and legal consequences of ignoring it are on the sender . Edit: " sender " here refers to the sender of the electronic notification .
In this case the consequence is that the Australian government agency collecting the import tax doesn't get paid. Which means that they don't release the package to FedEx, and that you don't get your package. FedEx needs to do a better job with these notifications. At the very least they need to hire a copywriter.
Then about five months later, I got a bill from FedEx for import fees, tax and service charges. Had to fight with FedEx for some time about it but eventually they agreed to void the bill. At this point in time, I have no idea if I paid the taxes when I bought the stuff, if FedEx paid them out of pocket or if the sender paid them out of pocket.