What are the WCAG principles relevant to email?

WCAG (Web Content Accessibility Guidelines) organizes accessibility around four principles: Perceivable, Operable, Understandable, Robust-often summarized as POUR. While designed for web, these apply directly to email.

Perceivable: Users must be able to perceive content-provide alt text, ensure color contrast, don't rely on color alone. Operable: Navigation must work with various inputs-keyboard accessible, no time limits, no seizure-inducing content. Understandable: Content must be comprehensible-clear language, consistent navigation, predictable behavior. Robust: Content must work with assistive technology-valid HTML, semantic structure.

WCAG provides a framework, not just a checklist. Understanding the principles helps you make good decisions in situations the guidelines don't specifically address. Email has unique constraints (limited interactivity, HTML rendering quirks), but POUR principles still guide accessible design choices.