ISSUEWhen running a DDP, the following error might occur:
The SMTP server requires a secure connection or the client was not authenticated. The server response was: 5.5.1 Authentication Required.
Option 1Disable 2-step authentication or use another email that does not have the 2-step feature on.
Option 2If using a Google domain, create a more complex password (include combination of uppercase letters and symbols)t. If the issue persists, try the following:
While logged into Gmail, click the account picture in the top-right corner and navigate to My Account > Sign-In & Security. Scroll down and click "2-Step Verification" > App-Specific Passwords > Manage application-specific passwords > Create new App password. Use the new password in the SMTP delivery option settings.