Bulk Email API allows you to send large volumes of emails programmatically, typically used for marketing campaigns, transactional emails, newsletters, and more. These APIs provide developers with the tools to integrate email sending functionality into their applications or systems seamlessly. Popular email service providers like SendGrid, Mailchimp, Amazon SES, and others offer Bulk Email APIs that enable you to send emails in bulk efficiently and reliably. These APIs usually provide features such as email template management, email list management, delivery tracking, analytics, and more.