SMTP Relay Services
SMTP Relay Services are third-party or self-hosted tools that facilitate the reliable delivery of email by acting as an intermediary between an email sender's server and recipient servers. They handle authentication, security, and delivery optimization to ensure emails reach inboxes without being flagged as spam. These services are essential for applications that send transactional or marketing emails at scale.
Developers should use SMTP Relay Services when building applications that send automated emails, such as password resets, notifications, or newsletters, to improve deliverability and avoid email blacklisting. They are crucial for handling high-volume email sending, managing bounce rates, and ensuring compliance with email service provider policies like those from Gmail or Outlook.