Where are these logs you all mention?

Tags: #<Tag:0x00007efff5e0ab18>

GOT IT!

Googled it and found this link:

SUMMARY:

  1. Login to WHM
  2. Navigate to interface WHM Home > Security Center > SMTP Restrictions
  3. 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?