Well yes, this is achievable.

The short version of it is:

1. Create new credentials in Google API and Services for this purpose
2. Tell odoo that the new authentication is OAuth and get the new tokens and test connection in the Outgoing Mail Connections

If you're behind an ssl server beware of what you've defined for your company's domain. Use https and not only http.

If you use nginx beware of URI mismatch messages. You'll probably have to resort to use both www.yourdomain.extension as well as yourdomain.extension in the server_name variable.

Oh And do not forget to use an alias for your user in your workspace, this is important. And it will have to match with the company -email you define in odoo's company definition. NOTE: This is NOT the user's alias in the workspace users details. This is the settings in your gmail account. as in: https://mail.google.com/mail/u/0/#settings/accounts

This worked for me.

For the long version I hope to share with you a step by step version that I want to have saved in my own knowledge base.