- Export your Gmail data.
- Create an e-mail forwarding rule for your Gmail inbox to relay all messages to mailbox.org automatically. Optionally, also create an auto-responder message to inform senders of your new mailbox.org address.
- Import your data to mailbox.org.
- Inform your friends and associates about your new e-mail address.
- Respond to forwarded e-mails from your Gmail account with your new mailbox.org address.
- Systematically remove your Gmail address from online services and replace it with your mailbox.org address or special aliases.
- After a while, ask Google to delete all your data in accordance with German European general data protection regulations (GDPR/DSGVO).
- Heads-up for those who use Google 2-Step-Verification.
See here for more information:
7. After a while, ask Google to delete all your data in accordance with
European general data protection regulations (GDPR/DSGVO).
You should allow a bit of time for the transition from Gmail to mailbox.org. Once you are confident everything works fine, you can ask Google to delete all data they have stored about you. Click on the following link to start this process: https://security.google.com/settings/security/deleteaccount
Please make sure to read carefully the information provided by Google about the deletion process.