One main use cases of Amazon SES is sending out transactional mails. Transactional mails are emails that get send based on a specific user action or a fixed event. Think sign up confirmations, data export mails, appointment reminders, breaking change notices, post experience surveys or shopping basket overviews.
In direct comparison to marketing emails the receiver has a vested interest in receiving transactional mails. This is why no explicit Einstimmung is needed to send them out. Because of the legit intend of transactional mails, they don't get classified as marketing materials by email inbox providers. Furthermore they are usually associated with extremely high opening rates. This makes them an even more relevant touchpoint for transporting your brand and creating a positive customer experience.