A few easy tips on suspect emails: If it looks suspicious it probably is.
Think; Any genuine bank credit card or service provider knows who you are. "Dear Customer" is a dead giveaway.
Such companies will not email you, if there is a real problem they will write on company letterhead with credential details, including your name, account number, and their address/phone number that you can check on your bills.
Look at the e-address it has come from, is it the genuine address for that company?
Hover your mouse over the link (DO NOT click it), it will be obviously bogus, probably just an ISP number.
If an "Offer" looks to good to be true, it is. They are targeting the gullible and the greedy.
There are a few cleverer ones to look out for. ie: when about to view a video clip you get a pop up window with Adobe logo telling you your Flash Player is out of date and an "Update Now" button. It pays to know your current Flash Player version, which is usually updated by Windows anyway. Do not "Update", close window, and if in doubt check your version independently on Google. Pressing "Update" will mess your computer.
Unfortunately using a computer is a bit like driving a car, it is not sufficient just to know how to operate the controls, you also have to learn road-craft to navigate the hazards.