Dear Nuntapong Saengthian,
Thank you for enabling two-factor authentication for your Apple ID (s•••••@hotmail.com).
Two-factor authentication is an additional layer of security designed to prevent unauthorised access to your account and protect the photos, documents, and other data you store with Apple.
From now on, whenever you sign in with your Apple ID on a new device or browser, you will verify your identity by entering your password plus a six-digit verification code sent to your other devices or a trusted phone number. To learn more, read the FAQ.
Two-factor authentication was enabled on 12 December 2015 at 04:04:39 GMT.
If you did not enable two-factor authentication and believe an unauthorised user has accessed your account, use the link below to return to your previous security settings. This link is available for a limited time.
Turn off Two-Factor Authentication
Sincerely,
Apple Support