Email Service Provider (ESP)
An Email Service Provider (ESP) manages the servers, deliverability, and infrastructure needed to send and receive emails. ESPs handle the complex parts of email delivery including IP reputation management, bounce processing, spam filtering, and compliance with regulations.
Types of ESPs
Transactional ESPs focus on API-based sending for application emails like password resets and notifications. Marketing ESPs provide campaign management, templates, and segmentation for newsletters and promotional content. Modern platforms like Transmit handle both use cases in one system.
Related Terms
Email API
A programmatic interface for sending, receiving, and managing emails from your application code.
SMTP Relay
A third-party SMTP server that routes your outgoing emails through trusted IP infrastructure.
Transactional Email
Automated emails triggered by user actions like password resets and order confirmations.
Need help with email deliverability?
Transmit handles authentication, warmup, and reputation isolation automatically.