Cant send Email- (101)SMTP connect()

I used a wordpress plugin (Check Email) to see if my server has any issue with sending email but found no problem with server.After I configured my smtp as THIS I found the following error-
My Gmail Credentials is 100% correct.
SMTP ERROR: Failed to connect to server: Network is unreachable (101)SMTP connect() failed. https://github.com/PHPMailer/PHPMailer/wiki/Troubleshooting