Email Notifications Not Working

Trying to set up SuiteCRM for my nephews business. I currently use SuiteCRM in the company I work for. Trying to set up the outgoing email and keep getting the following email when I try to send a test email.

An email error occurred:SMTP connect() failed. https://github.com/PHPMailer/PHPMailer/wiki/Troubleshooting

Which SuiteCRM version are you using? Which SMTP are you using, Gmail?

Can you check suitecrm.log for errors?