Dear songchai suebsung,
Your Apple ID (smart_logo@yahoo.com ) was used to sign in to the Find My iPhone app on a new device.
Date and Time: September 28, 2014, 5:51 AM PDT
Device: iPhone 4
If you recently signed in to the Find My iPhone app, you can disregard this email.
If you have not signed in to Find My iPhone recently or you believe someone may have accessed your account, go to My Apple ID ( https://appleid.apple.com ) and change your password as soon as possible.
Apple Support