You may use alternative way to backup/forward/download your email in your Gmail as per below steps:
1. Log into your Gmail account.
2. Access to the Gmail Setting.
3. Select on the :Accounts and Import tab”.
4. Click on the “Add a POP3 mail account you own” in the POP3 section.
5. Enter your email and hit Next Step button.
6. Enter your information by refer to below example:
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Username: Your full email address
Password: Your email account Password
POP server: mail.yourdomain.com (where domain.com should replace with your domain name)
Port: 110
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7. Click “Add Account” to add your account.