Hi limnos thank you for the reply but what if them email itself we cant open i mean we forget the password of that email? What are the other option?
iCloud: Activation Lock - http://support.apple.com/kb/HT201365 - This is a security feature to deter re-selling of stolen devices.
Activation Lock: Removing a device from a previous owner’s account - https://support.apple.com/HT201441 - If an activation lock was put on a device, only the owner of the account that applied the lock can remove it.
If you forgot your Apple ID - https://support.apple.com/HT201354
If you forgot your Apple ID password - https://support.apple.com/HT201487
If you cannot remember your password to the email account then that is something you will have to resolve with the providers of the email service.
If you cannot get into the email account then you can try answering security questions.
Answer security questions on http://iforgot.apple.com
Apple is being very strict about giving access to phones because they were/are a popular item for thieves and the old system made it too easy for them to be reset for re-sale. If you are the original owner of this phone and have the original sales receipt you can go to an Apple service place and ask them if they will reset it for you.
Email activation lock forgotten
