Thanks you very much for your questions.
You can Access and manage your email right from your Amazon Kindle Fire HD8 or HD10 tablet. Here’s how to add and remove email accounts.
If you’ve changed the password for an email account you use on your Amazon Kindle Fire tablet, message sending and retrieval will fail. You’ll have to change the password stored on the device too. Here’s how.

Adding an Email Account on kindle Fire

1. First, Open the “Email” app.
2. Then, If you haven’t setup an email account yet, you will be prompted to select an email provider. If you have already setup an email account, you will have to select “Menu” Android menu button > “Settings” > “Add account“.
3. Finally, Type the email address and password for the account you wish to add, then select “Next“. For POP3, iMAP, or Exchange email addresses, select the “Advanced Setup” option. You may need to obtain the server settings from your email provider.

You have done all works.

Changing an Email Account on kindle Fire

1. First Open the “Email” app from the Home screen.
2. Then From the list of messages “Menu” Android menu button > “Settings“.
3. After then Select the account you wish to change under the “Accounts” section.
4. Next You’ll have to change the password under the “Incoming server” and “Outgoing server options.
5. Finally, Once you have changed the password under each option, tap “Done” and the password will be stored.

You have done all works.

Deleting an Email Account on kindle Fire

1. First, Open the “Email” app.
2. Then, Tap “Menu” Android menu button > “Settings”
3. After then, Tap the email account you wish to remove.
4. Next, Scroll all the way to the bottom and select the option to “Delete Account from Device”, and the account will be deleted.
5. Finally, This post applies to the Kindle Fire HD8 and HD10 devices.

You have done all works.

Reset Change or delete email from your kindile fire.

1. Go to Manage
2. Your Content and Devices. From Settings,
3. Scroll down to Personal Document Settings.
4. Under Send-to-Kindle Email Settings, your Send to Kindle email address will be listed.
5. To change this email address, click Edit next to your device, enter a new email address,
6. and then click Save to save your changes.

Thanks for the questions.