I started in the same position mate. My old Gmail is still there but rarely gets anything. My email transition was like thweek s:
- Set up auto forward to your new email system.
- Reply to people and companies you actually know from your gmail account, cc your new account saying that you've migrated. Peicemeal update your user details.with companies like utilities, rent, banks, and other logins.
- Set up auto reply after about 3 months to say that the account is only monitored weekly and you'll reply when you check.
- Rinse & repeat step 2.