Lettr - Email API

Send transactional and marketing emails from your WordPress site using the Lettr email API. Lettr replaces the default WordPress email system with a reliable, developer-friendly API that delivers emails to inboxes — not spam folders. Why Lettr?

• Reliable email delivery — Built on battle-tested infrastructure with SPF, DKIM, and DMARC authentication out of the box.
• Simple setup — Connect your WordPress site with a single API key. No SMTP configuration needed.
• Transactional email at scale — Send password resets, order confirmations, notifications, and more through the Lettr email API.
• Real-time tracking — Monitor opens, clicks, bounces, and deliverability from the Lettr dashboard.
• Templates & personalization — Use the Lettr drag-and-drop editor and merge tags for dynamic content.
• Developer-first — RESTful API, detailed documentation, and SDKs for PHP, Node.js, Python, Go, Rust, Java, and Laravel.

How it works This plugin overrides the default WordPress wp_mail() function and routes all outgoing emails through the Lettr API. This means every email your site sends — including emails from WooCommerce, contact form plugins, and any other plugin — is delivered through Lettr automatically. Links

• Lettr Website
• Documentation
• API Reference

1.2.0

• Add campaigns API client methods (list, show, events, send, schedule, unschedule).

1.1.0

• Add audience API client methods (lists, contacts, topics, properties, segments).
• Bump tested-up-to to WordPress 7.0.

1.0.0

• Initial release.