I noticed the new 'Recent messages' section in my AdSense account. check this image,
and i check the news regards this from this page,
"If you've logged in to your account today, you've probably noticed the new 'Recent messages' section in your AdSense account. We're happy to let you know that this is your personal inbox where we'll send you customized optimization tips. More specifically, our system will automatically analyze your account and ad settings. Based on these findings, you'll receive a notification each month in your AdSense account if there are changes you can make to improve your overall AdSense performance.While we're not able to guarantee results from implementing these suggestions, we've found that these techniques have been successful for many publishers in the past which is why we've developed this feature for you. If you don't receive a notification during a specific month, don't worry. You've probably implemented all of our current suggestions and we'll be adding more tips in the future.Happy optimizing! "