The email system must authenticate before sending email error is a notification from your email application on your device which requires you verify settings on your email application in order to be able to send out emails.
To fix the email system must authenticate before sending email error, use the steps:
1. Open your the email application (Gmail, Outlook, Apple Mail, etc.) on your device
2. Open the Settings
3. On the Account Information – make sure your email address is typed in correctly and your email password is correct
4. On the Incoming mail (IMAP) and Outgoing mail (SMTP) settings – make sure the settings are correct
If you are using the POP3 protocol to connect your email address to an email app, use these steps:
1. Select the Send / Receive tab on your email app
2. In the Send & Receive group, click Send/Receive All Folders
Please note the naming structure depends on your email application.
If you’ve verified all of the settings are correct and the error is still being triggered, you can remove your email address from the email application and re-add it to clear it off.