How do I set up emails on Spree Commerce?

So I know I can install the mailer gem from here:

https://guides.spreecommerce.com/user/configuring_mail_methods.html

But it clearly says that generic action mailer settings are more favourable at the top of the page.

I have installed postmark which is sending emails fine in an extension I built. However Spree does not appear to be sending emails when I create an order for a customer. How can I turn these transactional emails on without the Spree mailer gem, as I want to use postmark on its own.

Also where the hell is the listed email section from the documentation?

https://guides.spreecommerce.com/developer/deployment_tips.html

Thanks for any help!

You can set up emails by adding the gem at https://github.com/spree-contrib/spree_mail_settings

Not sure if the message at the top of the page has been changed since this question was posted but it says to use that gem now.

Add gem 'spree_mail_settings', github: 'spree-contrib/spree_mail_settings' to you gemfile and you will get a new page in the admin settings for setting up your email