Gmail: forward all emails to another email address

1. Click on the Settings (Gear) icon at the top right corner of Gmail. Select Settings.
2. Click on the Forwarding and POP/IMAP tab.
3. In the Forwarding section, click on the Add a forwarding address button.
4. Input the destination email address in the dialogue to add it.
5. An email will be sent to the destination email address to ask for permission.
6. Login to the destination email account to retrieve that email. Click on the link given in that email, or fetch the Confirmation Code.
7. Go back to the forwarding email and enter the Forwarding and POP/IMAP setting again. Click on the radio button of Forward a copy of incoming mail to and select the destination email address. If you choose the Confirmation Code way, input the code to validate the email address.
8. There are some options to let you choose what to do with the original Gmail copy. E.g., you can keep a copy or delete the copy from the original Gmail account.