Email marketing glossary

Short, practitioner definitions for the terms used across Sendpath lessons. Each entry links back to the lessons where the concept is taught in context.

ESP

Email service provider: software for sending, templating, and often automating email.

AI-native ESP

An email platform built around brand-aware generation and agent operation, not a bolted-on writing assistant.

SPF

Sender Policy Framework: DNS record listing hosts allowed to send for a domain.

DKIM

DomainKeys Identified Mail: cryptographic signature that proves message integrity.

DMARC

Policy layer telling receivers what to do when SPF/DKIM fail, plus reporting.

Deliverability

The practice of earning inbox placement through authentication, reputation, and engagement quality.

Transactional email

Messages required to complete a user action or account process.

Lifecycle automation

Event-driven email flows tied to product and customer stages.

MJML

A markup language that compiles to responsive email HTML.

MCP for email

Model Context Protocol servers that let AI agents operate email platforms.