{"templateId":"markdown","sharedDataIds":{"sidebar":"sidebar-docs/email-api/sidebars.yaml"},"props":{"metadata":{"markdoc":{"tagList":["admonition"]},"type":"markdown"},"seo":{"title":"Send API JSON Properties - Mailjet Send API v3","siteUrl":"https://dev.mailjet.com/","projectTitle":"Mailjet Developer Documentation","description":"Complete reference for every JSON property accepted by the Mailjet Send API v3 payload, with types, descriptions, and constraints for each field.","image":"https://dev.mailjet.com/og-image.png","lang":"en-US","keywords":["Mailjet API","Email API","Content API","SMTP Relay","transactional email","email delivery","Send API","email templates","developer documentation"],"meta":[{"name":"og:type","content":"website"},{"name":"og:site_name","content":"Mailjet Developer Documentation"},{"name":"twitter:card","content":"summary_large_image"},{"name":"robots","content":"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1"},{"name":"googlebot","content":"index, follow, max-snippet:-1, max-image-preview:large"}],"jsonLd":{"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://dev.mailjet.com/#organization","name":"Mailjet","alternateName":"Sinch Mailjet","url":"https://www.mailjet.com","logo":"https://assets.mailjet.com/lib/images/mailjetLogo/mj_logo_with_text_color.png","parentOrganization":{"@type":"Organization","name":"Sinch","url":"https://www.sinch.com"}},{"@type":"WebSite","@id":"https://dev.mailjet.com/#website","name":"Mailjet Developer Documentation","description":"Official developer documentation for the Mailjet Email API, Content API and SMTP Relay.","url":"https://dev.mailjet.com/","inLanguage":"en-US","publisher":{"@id":"https://dev.mailjet.com/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://dev.mailjet.com/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]},"llmstxt":{"hide":false,"title":"Mailjet Developer Documentation","description":"Developer documentation for the Mailjet Email API, Content API and SMTP Relay - guides, API references and code samples for sending, templating and tracking email at scale.","details":{"content":"Mailjet (part of Sinch) provides APIs for sending and managing email.\n\nThis documentation covers four main areas:\n\n- **Email API** - the Send API (v3 and v3.1) for transactional and marketing email,\n  plus contact management, segmentation, campaigns, statistics, webhooks, the Parse API\n  and the Mailjet Templating Language.\n- **Content API** - programmatic management of email templates, template contents,\n  images, labels and authentication tokens (v1).\n- **SMTP Relay** - sending through Mailjet's SMTP servers, including custom headers.\n- **API Reference** - the complete, generated reference for every endpoint, built directly\n  from the OpenAPI specifications.\n\nBase URL for all REST APIs: `https://api.mailjet.com`.\nAuthentication uses HTTP Basic auth with an API key and secret key.\n\n## Machine-readable entry points\n\nPrefer these when you need the API surface in as few requests as possible:\n\n- `/openapi/openapi-mailjet.md` - the **complete** Email API reference (every endpoint,\n  grouped by resource) as a single Markdown document.\n- `/openapi/openapi-passport.md` - the **complete** Content API reference as a single\n  Markdown document.\n- `/_bundle/openapi/openapi-mailjet.yaml` - the raw, fully bundled OpenAPI 3 description\n  of the Email API.\n- `/_bundle/openapi/openapi-passport.yaml` - the raw, fully bundled OpenAPI 3 description\n  of the Content API.\n- `/sitemap.xml` - every indexable URL on this site.\n\nEvery page on this site is also available as clean Markdown by appending `.md` to its URL."},"sections":[{"title":"Email API","description":"Sending, contacts, campaigns, statistics, webhooks and templating.","includeFiles":["docs/email-api/**/*.md"],"excludeFiles":[]},{"title":"Content API","description":"Manage templates, template contents, images, labels and tokens.","includeFiles":["docs/content-api/**/*.md","docs/content-api.md"],"excludeFiles":[]},{"title":"SMTP Relay","description":"Send email through Mailjet's SMTP servers.","includeFiles":["docs/smtp-relay/**/*.md"],"excludeFiles":[]},{"title":"API Reference","description":"Complete generated reference for every Mailjet API endpoint.","includeFiles":["openapi/openapi-mailjet.yaml","openapi/openapi-passport.yaml","docs/api-reference/**/*.md"],"excludeFiles":[]},{"title":"Migrating from Mandrill","description":"Guides for switching from Mandrill to Mailjet.","includeFiles":["docs/mandrill/**/*.md"],"excludeFiles":[]}],"excludeFiles":[]}},"dynamicMarkdocComponents":[],"compilationErrors":[],"ast":{"$$mdtype":"Tag","name":"article","attributes":{},"children":[{"$$mdtype":"Tag","name":"Admonition","attributes":{"type":"info","name":"Info"},"children":[{"$$mdtype":"Tag","name":"p","attributes":{},"children":["The following adheres to Send API v3.0"]}]},{"$$mdtype":"Tag","name":"Heading","attributes":{"level":1,"id":"send-api-json-properties","__idx":0},"children":["Send API JSON properties"]},{"$$mdtype":"Tag","name":"p","attributes":{},"children":["Full descriptions of the properties of each message."]},{"$$mdtype":"Tag","name":"Heading","attributes":{"level":2,"id":"send-api-errors","__idx":1},"children":["Send API Errors"]},{"$$mdtype":"Tag","name":"div","attributes":{"className":"md-table-wrapper"},"children":[{"$$mdtype":"Tag","name":"table","attributes":{"className":"md"},"children":[{"$$mdtype":"Tag","name":"thead","attributes":{},"children":[{"$$mdtype":"Tag","name":"tr","attributes":{},"children":[{"$$mdtype":"Tag","name":"th","attributes":{"data-label":"Error Code"},"children":["Error Code"]},{"$$mdtype":"Tag","name":"th","attributes":{"data-label":"Message"},"children":["Message"]},{"$$mdtype":"Tag","name":"th","attributes":{"data-label":"Reason"},"children":["Reason"]}]}]},{"$$mdtype":"Tag","name":"tbody","attributes":{},"children":[{"$$mdtype":"Tag","name":"tr","attributes":{},"children":[{"$$mdtype":"Tag","name":"td","attributes":{},"children":["400"]},{"$$mdtype":"Tag","name":"td","attributes":{},"children":["Invalid characters detected"]},{"$$mdtype":"Tag","name":"td","attributes":{},"children":["A non UTF-8 character was detected"]}]},{"$$mdtype":"Tag","name":"tr","attributes":{},"children":[{"$$mdtype":"Tag","name":"td","attributes":{},"children":["400"]},{"$$mdtype":"Tag","name":"td","attributes":{},"children":["\"Headers\" is not JSON object type"]},{"$$mdtype":"Tag","name":"td","attributes":{},"children":["The Headers property should follow the format {\"X-My-Header\":\"my own value\",\"X-My-Header-2\":\"my own value 2\"}"]}]},{"$$mdtype":"Tag","name":"tr","attributes":{},"children":[{"$$mdtype":"Tag","name":"td","attributes":{},"children":["400"]},{"$$mdtype":"Tag","name":"td","attributes":{},"children":["Header [Property name] is not string type"]},{"$$mdtype":"Tag","name":"td","attributes":{},"children":[]}]},{"$$mdtype":"Tag","name":"tr","attributes":{},"children":[{"$$mdtype":"Tag","name":"td","attributes":{},"children":["400"]},{"$$mdtype":"Tag","name":"td","attributes":{},"children":["Missing \"To\" or \"Recipients\" property"]},{"$$mdtype":"Tag","name":"td","attributes":{},"children":["Send API must be called with either \"To\" or \"Recipient\" properties"]}]},{"$$mdtype":"Tag","name":"tr","attributes":{},"children":[{"$$mdtype":"Tag","name":"td","attributes":{},"children":["400"]},{"$$mdtype":"Tag","name":"td","attributes":{},"children":["Too many recipients in To, Too many recipients in Cc, Too many recipients in Bcc"]},{"$$mdtype":"Tag","name":"td","attributes":{},"children":["To, Cc and Bcc can't exceed 50 Email addresses"]}]}]}]}]}]},"headings":[{"value":"Send API JSON properties","id":"send-api-json-properties","depth":1},{"value":"Send API Errors","id":"send-api-errors","depth":2}],"frontmatter":{"title":"Send API json properties","desription":"Full descriptions of the properties.","seo":{"title":"Send API JSON Properties - Mailjet Send API v3","description":"Complete reference for every JSON property accepted by the Mailjet Send API v3 payload, with types, descriptions, and constraints for each field."}},"lastModified":"2026-08-26T10:53:57.000Z","pagePropGetterError":{"message":"","name":""}},"slug":"/docs/email-api/send-api-v3/send-api-json-props","userData":{"isAuthenticated":false,"teams":["anonymous"]},"isPublic":true}