Sending goes through Amazon SES. Delivered/opened/clicked tracking needs an SES Configuration Set with event publishing (Delivery, Bounce, Complaint, Open, Click) to an SNS topic, with that topic's HTTPS subscription pointed at the webhook URL below -- and Open/Click tracking switched on in the Configuration Set itself, which is what makes SES inject the tracking pixel and rewrite links automatically.

SNS webhook URL (subscribe your Configuration Set's SNS topic to this)