Googled it and found this link:
- Login to WHM
- Navigate to interface WHM Home > Security Center > SMTP Restrictions
- If the protection is enabled, click the “Disable” button
Mine was set to “Enable”
Ran PHPlist using port 465, SSL - SUCCESS!
Thank you duncanc for your patient attempts to help this poor guy. Make a note of this solution.
Is there a way to request this information be added to the PHPlist/PHPMailer manuals or to the github troubleshooting guide?