Often these fraudulent emails referred to as phishing attempts, come from companies you may never have done business with, thereby making the fraud attempt easy to spot. But every once in a while, the fraudsters may get lucky and trick you into clicking on the wrong link before you catch on.
The easiest way to avoid falling victim to one of these phishing scams is to "hover before you click." In other words, before clicking on any link in an email you're not quite sure about, hold your cursor over the link for a moment. When you hover over the link, a pop-up will appear that will show you the true destination of the link.
For example, you receive an email from what appears to be PayPal asking you to update your information. You just happen to have a PayPal account so your first instinct is to click on the link to follow the steps. STOP! Before you click on anything, hover over the link and see whether it's actually directing you to PayPal. If it's not, or if anything else about the email seems unusual, it's best just to delete it without clicking on anything.
If you suspect the request may have been legitimate, simply contact the company directly via its website or over the phone. That way you can be sure you're dealing with the real company.