Can’t get this plugin to work!

Installed plugin. Created Google API as instructed but final verification step sends us back to our site on a 404 Error page.

Then tried via SMTP or our domain name (@oursite.com) but still no luck.

Now we tested SMTP via @gmail but still errors when testing.

Can someone please tell us how to fix these errors? Here’s a copy of what we see when we test the email:

Versions:
WordPress: 4.9.1
WordPress MS: No
PHP: 5.6.31
WP Mail SMTP: 1.1.0

PHPMailer:
Mailer: smtp
ErrorInfo: SMTP connect() failed. https://github.com/PHPMailer/PHPMailer/wiki/Troubleshooting
Host: smtp.gmail.com
Port: 587
SMTPSecure: tls
SMTPAutoTLS: bool(true)
SMTPAuth: bool(true)

SMTP Debug:
2017-12-19 07:16:59 Invalid address: (setFrom)
2017-12-19 07:16:59 Connection: opening to smtp.gmail.com:587, timeout=300, options=array (
)
2017-12-19 07:17:01 Connection: Failed to connect to server. Error number 2. “Error notice: stream_socket_client(): unable to connect to smtp.gmail.com:587 (Network is unreachable)
2017-12-19 07:17:01 SMTP ERROR: Failed to connect to server: Network is unreachable (101)
2017-12-19 07:17:01 SMTP connect() failed. https://github.com/PHPMailer/PHPMailer/wiki/Troubleshooting