{"id":10753,"date":"2026-05-20T00:29:57","date_gmt":"2026-05-19T16:29:57","guid":{"rendered":"https:\/\/aeosub.com\/lettr\/"},"modified":"2026-05-20T00:29:57","modified_gmt":"2026-05-19T16:29:57","slug":"lettr","status":"publish","type":"post","link":"https:\/\/aeosub.com\/zh\/lettr\/","title":{"rendered":"Lettr &#8211; Email API"},"content":{"rendered":"<div class=\"plugin-info-card\" style=\"border: 1px solid #e2e8f0;border-radius: 10px;overflow: hidden;margin-bottom: 30px;font-family: -apple-system, system-ui, sans-serif;background: #fff\">\n<table style=\"width: 100%;border-collapse: collapse;font-size: 14px\">\n<tr style=\"border-bottom: 1px solid #edf2f7\">\n<th style=\"padding: 15px 20px;text-align: left;width: 35%;color: #4a5568;background: #fcfcfc\"><img decoding=\"async\" src=\"https:\/\/s.w.org\/plugins\/geopattern-icon\/lettr.svg\" style=\"width: 40px;height: 40px;border-radius: 6px;margin-right: 12px;vertical-align: middle\"> Developer<\/th>\n<td style=\"padding: 15px 20px;font-weight: 500\"><a href=\"https:\/\/profiles.wordpress.org\/vojtechj\/\" target=\"_blank\" rel=\"noopener\">vojtechj<\/a><\/td>\n<\/tr>\n<tr style=\"border-bottom: 1px solid #edf2f7\">\n<th style=\"padding: 12px 20px;text-align: left;color: #4a5568;background: #fcfcfc\">Version<\/th>\n<td style=\"padding: 12px 20px\">v1.0.0<\/td>\n<\/tr>\n<tr style=\"border-bottom: 1px solid #edf2f7\">\n<th style=\"padding: 12px 20px;text-align: left;color: #4a5568;background: #fcfcfc\">Active Installs<\/th>\n<td style=\"padding: 12px 20px\">0 +<\/td>\n<\/tr>\n<tr style=\"border-bottom: 1px solid #edf2f7\">\n<th style=\"padding: 12px 20px;text-align: left;color: #4a5568;background: #fcfcfc\">Requires \/ Tested<\/th>\n<td style=\"padding: 12px 20px\">5.8 \/ 6.9.4<\/td>\n<\/tr>\n<tr style=\"border-bottom: 1px solid #edf2f7\">\n<th style=\"padding: 12px 20px;text-align: left;color: #4a5568;background: #fcfcfc\">Last Updated<\/th>\n<td style=\"padding: 12px 20px\">2026-05-19 3:32pm GMT<\/td>\n<\/tr>\n<tr>\n<th style=\"padding: 12px 20px;text-align: left;color: #4a5568;background: #fcfcfc\">Official Link<\/th>\n<td style=\"padding: 12px 20px\"><a href=\"https:\/\/wordpress.org\/plugins\/lettr\/\" target=\"_blank\" style=\"text-decoration: none;color: #4a3bca;font-weight: bold\" rel=\"noopener\">View Details \u2192<\/a><\/td>\n<\/tr>\n<\/table><\/div>\n<div class=\"plugin-short-desc\" style=\"margin: 20px 0;padding: 12px 15px;background: #f9fafb;border-left: 4px solid #4a3bca;border-radius: 6px;font-style: italic;color: #4a5568\">Send transactional emails from your site through the Lettr email API.<\/div>\n<p>Send transactional and marketing emails from your WordPress site using the <a href=\"https:\/\/lettr.com\" rel=\"nofollow ugc noopener\" target=\"_blank\">Lettr<\/a> email API. Lettr replaces the default WordPress email system with a reliable, developer-friendly API that delivers emails to inboxes \u2014 not spam folders.<\/p>\n<h4>Why Lettr?<\/h4>\n<ul>\n<li><strong>Reliable email delivery<\/strong> \u2014 Built on battle-tested infrastructure with SPF, DKIM, and DMARC authentication out of the box.<\/li>\n<li><strong>Simple setup<\/strong> \u2014 Connect your WordPress site with a single API key. No SMTP configuration needed.<\/li>\n<li><strong>Transactional email at scale<\/strong> \u2014 Send password resets, order confirmations, notifications, and more through the Lettr email API.<\/li>\n<li><strong>Real-time tracking<\/strong> \u2014 Monitor opens, clicks, bounces, and deliverability from the Lettr dashboard.<\/li>\n<li><strong>Templates &amp; personalization<\/strong> \u2014 Use the Lettr drag-and-drop editor and merge tags for dynamic content.<\/li>\n<li><strong>Developer-first<\/strong> \u2014 RESTful API, detailed documentation, and SDKs for PHP, Node.js, Python, Go, Rust, Java, and Laravel.<\/li>\n<\/ul>\n<h4>How it works<\/h4>\n<p>This plugin overrides the default WordPress <code>wp_mail()<\/code> function and routes all outgoing emails through the Lettr API. This means every email your site sends \u2014 including emails from WooCommerce, contact form plugins, and any other plugin \u2014 is delivered through Lettr automatically.<\/p>\n<h4>Links<\/h4>\n<ul>\n<li><a href=\"https:\/\/lettr.com\" rel=\"nofollow ugc noopener\" target=\"_blank\">Lettr Website<\/a><\/li>\n<li><a href=\"https:\/\/docs.lettr.com\" rel=\"nofollow ugc noopener\" target=\"_blank\">Documentation<\/a><\/li>\n<li><a href=\"https:\/\/docs.lettr.com\/api-reference\/introduction\" rel=\"nofollow ugc noopener\" target=\"_blank\">API Reference<\/a><\/li>\n<\/ul>\n<h3>External services<\/h3>\n<p>This plugin connects to the Lettr API at <code>app.lettr.com<\/code> to deliver email on behalf of your WordPress site. Each time <code>wp_mail()<\/code> is invoked, the plugin sends the following data to Lettr over HTTPS so that Lettr can process and deliver the message:<\/p>\n<ul>\n<li>The configured sender email address and name<\/li>\n<li>Recipient, CC, BCC, and Reply-To addresses<\/li>\n<li>The email subject, HTML and\/or plain text body, and any attachments<\/li>\n<li>Any custom email headers, tags, or metadata supplied by the calling code<\/li>\n<li>Your Lettr API key (sent as a Bearer token in the <code>Authorization<\/code> header for authentication)<\/li>\n<\/ul>\n<p>The plugin also calls <code>app.lettr.com\/api\/auth\/check<\/code> to validate the API key when you save it on the settings screen.<\/p>\n<p>This service is provided by Lettr. By using this plugin you agree to Lettr&#8217;s terms and acknowledge their privacy practices:<\/p>\n<ul>\n<li>Terms of Service: <a href=\"https:\/\/lettr.com\/terms\" rel=\"nofollow ugc noopener\" target=\"_blank\">https:\/\/lettr.com\/terms<\/a><\/li>\n<li>Privacy Policy: <a href=\"https:\/\/lettr.com\/privacy-policy\" rel=\"nofollow ugc noopener\" target=\"_blank\">https:\/\/lettr.com\/privacy-policy<\/a><\/li>\n<\/ul>","protected":false},"excerpt":{"rendered":"<p>Send transactional emails from your site through the Lettr email API.<\/p>","protected":false},"author":1,"featured_media":9317,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"inline_featured_image":false,"footnotes":""},"categories":[252],"tags":[736,1396,1397,740,1398,555],"class_list":["post-10753","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-trends","tag-email","tag-email-api","tag-lettr","tag-smtp","tag-transactional-email","tag-wordpress-plugin"],"_links":{"self":[{"href":"https:\/\/aeosub.com\/zh\/wp-json\/wp\/v2\/posts\/10753","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/aeosub.com\/zh\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/aeosub.com\/zh\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/aeosub.com\/zh\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/aeosub.com\/zh\/wp-json\/wp\/v2\/comments?post=10753"}],"version-history":[{"count":0,"href":"https:\/\/aeosub.com\/zh\/wp-json\/wp\/v2\/posts\/10753\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/aeosub.com\/zh\/wp-json\/wp\/v2\/media\/9317"}],"wp:attachment":[{"href":"https:\/\/aeosub.com\/zh\/wp-json\/wp\/v2\/media?parent=10753"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/aeosub.com\/zh\/wp-json\/wp\/v2\/categories?post=10753"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/aeosub.com\/zh\/wp-json\/wp\/v2\/tags?post=10753"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}