Postmark is a transactional email delivery service designed for developers and businesses that rely on sending emails triggered by application events. Unlike bulk email providers, Postmark specializes in high-volume, time-sensitive emails like password resets, order confirmations, welcome emails, and shipping notifications. Its primary focus is on ensuring these critical emails reach their intended recipients reliably and quickly.

The service provides a robust API that integrates seamlessly into various applications and platforms. Developers can leverage Postmark's infrastructure to send emails programmatically, gaining control over the content, timing, and delivery of each message. This approach is crucial for applications where email is an integral part of the user experience or operational workflow.

Postmark also emphasizes a clean sending reputation and actively works to combat spam and bounces. This dedication to deliverability means businesses can trust that their important communications will arrive in the inbox, rather than the spam folder, helping to maintain user engagement and trust.