Struggling to set-up SMTP Configuration
you have a problem outside of civicrm realm: you are trying to send an email from a domain name that has a SPF record that doesn't include your server IP address.

it is the domain that you have set up for the bounce that needs to have the SPF record.

However, before you go down that rabbit hole: google has limitations on how many emails you can sent via their smtp server. It will never work for a production configuration as soon as you have more than a handful of contacts you want to mail.

I would suggest you to use an external provider to do the mailing (they are lots of providers (civismtp, sendgrid, mailjet...) that can easily be integrated with your civicrm that you can use.