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.
- 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.
- WordPress 5.8 or higher
- PHP 7.2 or higher
- A Lettr account and API key
Option A: Upload via WordPress Admin Panel
- Download the plugin as a ZIP.
- In your WordPress admin panel, go to Plugins → Add Plugin → Upload Plugin, upload the ZIP, press Install, and activate the plugin once installed.
Option B: Manual install
- Clone or extract the plugin into
/wp-content/plugins/lettr. - Activate the plugin via the
Pluginspage.
- Once the plugin is activated, you are automatically redirected to the plugin's setup page.
- Follow the step-by-step guide on the page to connect Lettr to your site.
- Enter your API key from the Lettr dashboard and configure your sender name and email address.
- Send a test email to verify everything is working.
All outgoing WordPress emails (wp_mail) will now be sent through the Lettr API automatically — including emails from WooCommerce, contact form plugins, and any other plugin that uses the standard WordPress mail function.
For questions, bug reports, or feature requests, visit lettr.com.
GPL-2.0-or-later