Amazon SES
Amazon SES deploys pay-for-only-what-you-use concept for its SES. It uses the SMTP or a simple API call for easy and fast delivering the email. It notifies its users about successful and unsuccessful email deliveries. It deploys a mailbox simulator to test the efficiency of its user’s applications to handle several situations such as hard bounce, an out-of-office auto response, a complaint or a successful email acceptance.