Set 2F Authentication in Google account
when you go to 2-Step Verification scroll down to the App Passwords.
now click to Create to generate the 16-digit code
After that, open the Email Settings tab in Preferences[F12] and click to Switch to Advanced Settings
Enable the Use SMTP Authentication and Require secure authentication checkboxes
And insert the generated App Password - 16-digit code for SMTP Password
Now you can Send Test Email