Transfer Gmail Messages to another Gmail Address
Open your new Gmail Account Go to Settings >Accounts and Import “Choose check mail from other Account”
Select “Add POP3 mail account you own “now a window will pop up add your old Gmail Address in the Text box and hit next Step.
Gmail will ask for your old email Password Enter your old account Gmail Password and check “Lave a copy of retrieved messages on the server” and “label incoming messages” so gmail will label the emails that you copy from the old email. it will help you to understand which emails are downloaded from old Email.