Before you delete your account: Review the info in your account. Learn how to download data that you want to keep. If you use your Gmail address for online banking, social media, or apps, add a new email address for these services. Update your account recovery info in case you try to recover your account later. Learn how to add recovery info.
How to Remove Google Account from other's Device 2020 Apr 15, 2019 Clean Up Email Addresses in Your Gmail Auto-complete List Change or remove an email address. In Gmail, in the top-left corner, click on the dropdown arrow next to Gmail (for some, it may say Mail) and choose Contacts. Then click into the contact that you want to delete. You have a few options.
Moreover, if you forget to remove Gmail account from your phone then the new owner will be able to use all the services that are linked with Google. After you have removed the Gmail account from your phone, it is recommended to cross check by opening some Google Services like Gmail or Play Store just to make sure they are not accessible anymore.
How to delete a Gmail account and Google Account Sep 29, 2018
Tip: Before you remove a connected account from Outlook.com, we recommend that you sign in to the account via the original email provider and make sure your email messages are there.If they are there, after you remove your account you can delete all the account's email messages from Outlook.com and you'll still have a copy of them at your email provider.
**You may need to do some creative work, but i think it can be done. First, create a disposable email account. Make sure it works with Gmail and Google store. Then add it to your account as a backup.