Can never make this plugin work

I have tried every conceivable variable for the settings for this plugin yet it has never worked. It’s probably wonderful, but without making it function, it’s just wasting space.

2019-01-19 00:59:00 Connection: opening to mail.xxxxxxxx.org:465, timeout=300, options=array (
)
2019-01-19 00:59:00 Connection: opened
2019-01-19 01:01:45 SMTP -> get_lines(): $data is “”
2019-01-19 01:01:45 SMTP -> get_lines(): $str is “”
2019-01-19 01:01:45 SERVER -> CLIENT:
2019-01-19 01:01:45 SMTP NOTICE: EOF caught while checking if connected
2019-01-19 01:01:45 Connection: closed
2019-01-19 01:01:45 SMTP Error: Could not authenticate.
2019-01-19 01:01:45 SMTP connect() failed. https://github.com/PHPMailer/PHPMailer/wiki/Troubleshooting