FileWave Server Mail test receives Bad Request with Google SMTP Accounts

What
FileWave can send scheduled reports and test messages through the mail settings in FileWave preferences. Google SMTP accounts may return a Bad Request error during setup if the account is not ready for the app-password workflow shown below.
When/Why
For Google accounts, enable 2-Step Verification and create a Google App Password for FileWave. Use that generated app password in FileWave mail preferences instead of the user's normal Google password.
How
In the Google account, open the security settings, confirm that 2-Step Verification is enabled, then create an app password. Google's current instructions are here: Sign in with app passwords. Copy the generated password into FileWave email preferences and keep it stored securely with your other service-account credentials.
Send another test email from FileWave to confirm that the Google account and app password are accepted.
Related Links
Generating scheduled reports
Sending Scheduled Reports to More Than One Address
Configuring FileWave Server Basic Preferences