An Email Service Provider (ESP) is a company that offers services to send, receive, and manage email communications. These providers typically offer features such as email hosting, marketing tools, and analytics to help businesses and individuals effectively communicate with their audience. Popular examples of ESPs include Mailchimp, Constant Contact, and SendGrid. ESPs play a crucial role in digital marketing by allowing users to create and send newsletters, promotional emails, and automated messages. They help ensure that emails reach the intended recipients' inboxes while providing tools for tracking engagement and performance metrics, which can enhance overall communication strategies.