I saw the "a" difference after comparing the addresses for about 15 seconds, but would not have noticed without the tip that something was different. Another thing to do is hover your mouse pointer over any email address (sender) and the actual address behind it will pop up. Good advice to never click an attachment or link. Go to your online bank (or whatever the email is pushing you to click on) in another window. I've seen scams for Amazon purchases, UPS deliveries, PayPal accounts, and my favorite: "I have recorded you watching XXX"! 
