Shopify Email sends from inside the admin you already log into. Products, prices and images pull straight from the catalogue, the list is the customer list, and there is nothing to integrate or keep in sync.
Automations are handled through Shopify’s own marketing automations, which cover the common triggers with templates rather than a free-form builder. Segmentation uses Shopify customer segments, which are better than people expect and still narrower than a dedicated platform.