I had a genuine e-mail from Amazon once - something to do with a change of credit card - and it didn't mention my name. It arrived just as I placed an order, so I guessed it was probably genuine, but it was asking me to go to a site and enter my CC details. So I called Amazon's customer support and they checked, determined that it was genuine, and I was good to go.
That was my second ever call to Amazon. The first was about a shipping charge problem. It was sorted out over the phone, with an e-mail confirmation 15 minutes later and a very favourable interpretation of the difference in the charges credited to my account. I would unhesitatingly recommend their customer service, in the same way that I would unhesitatingly recommend disembowelling yourself rather than embarking on the nightmare journey to hell that is involved when attempting to get support from PayPal.
Age 55, retired July 1, 2012; DW is 59 and working for 4 more years. Current portfolio is 1950K split 50 stocks/20 bonds/30 cash. Renting house, no debts.