Postmark Sending API API

The Sending API API from Postmark — 4 operation(s) for sending api.

Operations 4

POST /email Postmark Send a single email #
POST /email/batch Postmark Send a batch of emails #
POST /email/withTemplate Postmark Send an email using a Template #
POST /email/batchWithTemplates Postmark Send a batch of email using templates. #

Work with this as data

Every API here is available over the APIs.io API and to AI agents over MCP.

MCP server

One button, every client — Claude, Cursor, VS Code and the rest.

https://apis.io/mcp

Tools for apis

7 MCP tools reach this
  • find_apisBrowse and filter every API in the catalog.
  • get_api_artifactsOne API's artifacts, grouped by type.
  • get_openapiThe primary OpenAPI for this API.
  • find_similar_apisAPIs that look like this one.
  • apis_io_searchSTART HERE — APIs, providers and tags for one query, each with its total.
  • resolveTurn a domain, URL or GitHub org into the provider it belongs to.
  • find_cohortsEvery scored population of providers in the catalog.
All 92 tools →

Call it yourself

curl for this page
This API
curl "https://apis.io/api/v1/apis/postmark-sending-api-api"
All apis
curl "https://apis.io/api/v1/apis?limit=25"

Discovery needs no key. Ratings and market analysis are Pro.

Get an API key

Free tier, no email required.

A second provider on the same verified email joins the account you already have.

OpenAPI Specification

postmark-sending-api-api-openapi.yml Raw ↑
openapi: 3.2.0
info:
  title: Postmark Server Sending API
  description: 'Postmark makes sending and receiving email

    incredibly easy.

    '
  version: 1.0.0
servers:
- url: https://api.postmarkapp.com/
tags:
- name: Sending API
paths:
  /email:
    post:
      operationId: sendEmail
      tags:
      - Sending API
      summary: Postmark Send a single email
      parameters:
      - name: X-Postmark-Server-Token
        required: true
        description: The token associated with the Server on which this request will operate.
        in: header
        schema:
          type: string
      responses:
        200:
          description: OK
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/SendEmailResponse'
        422:
          $ref: '#/components/responses/422'
        500:
          $ref: '#/components/responses/500'
      requestBody:
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/SendEmailRequest'
  /email/batch:
    post:
      operationId: sendEmailBatch
      tags:
      - Sending API
      summary: Postmark Send a batch of emails
      parameters:
      - name: X-Postmark-Server-Token
        required: true
        description: The token associated with the Server on which this request will operate.
        in: header
        schema:
          type: string
      responses:
        200:
          description: OK
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/SendEmailBatchResponse'
        422:
          $ref: '#/components/responses/422'
        500:
          $ref: '#/components/responses/500'
      requestBody:
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/SendEmailBatchRequest'
  /email/withTemplate:
    post:
      operationId: sendEmailWithTemplate
      tags:
      - Sending API
      summary: Postmark Send an email using a Template
      parameters:
      - name: X-Postmark-Server-Token
        required: true
        description: The token associated with the Server on which this request will operate.
        in: header
        schema:
          type: string
      responses:
        200:
          description: OK
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/SendEmailResponse'
        422:
          $ref: '#/components/responses/422'
        500:
          $ref: '#/components/responses/500'
      requestBody:
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/EmailWithTemplateRequest'
        required: true
  /email/batchWithTemplates:
    post:
      operationId: sendEmailBatchWithTemplates
      tags:
      - Sending API
      summary: Postmark Send a batch of email using templates.
      parameters:
      - name: X-Postmark-Server-Token
        required: true
        description: The token associated with the Server on which this request will operate.
        in: header
        schema:
          type: string
      responses:
        200:
          description: OK
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/SendEmailBatchResponse'
        422:
          $ref: '#/components/responses/422'
        500:
          $ref: '#/components/responses/500'
      requestBody:
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/SendEmailTemplatedBatchRequest'
        required: true
components:
  schemas:
    SendEmailBatchRequest:
      type: array
      items:
        $ref: '#/components/schemas/SendEmailRequest'
    MessageHeader:
      description: A single header for an email message.
      properties:
        Name:
          description: The header's name.
          type: string
        Value:
          description: The header's value.
          type: string
    SendEmailResponse:
      description: The standard response when a postmark message is sent
      properties:
        To:
          type: string
        SubmittedAt:
          type: string
          format: date-time
        MessageID:
          type: string
        ErrorCode:
          type: integer
        Message:
          type: string
    HeaderCollection:
      type: array
      items:
        $ref: '#/components/schemas/MessageHeader'
    EmailWithTemplateRequest:
      properties:
        TemplateId:
          description: Required if 'TemplateAlias' is not specified.
          type: integer
        TemplateAlias:
          description: Required if 'TemplateId' is not specified.
          type: string
        TemplateModel:
          type: object
        InlineCss:
          type: boolean
          default: true
        From:
          type: string
          format: email
        To:
          type: string
          format: email
        Cc:
          type: string
          format: email
        Bcc:
          type: string
          format: email
        Tag:
          type: string
        ReplyTo:
          type: string
        Headers:
          $ref: '#/components/schemas/HeaderCollection'
        TrackOpens:
          description: Activate open tracking for this email.
          type: boolean
        TrackLinks:
          description: Replace links in content to enable "click tracking" stats. Default is 'null', which uses the server's LinkTracking setting'.
          type: string
          enum:
          - None
          - HtmlAndText
          - HtmlOnly
          - TextOnly
        Attachments:
          $ref: '#/components/schemas/AttachmentCollection'
      required:
      - TemplateId
      - TemplateAlias
      - TemplateModel
      - To
      - From
    AttachmentCollection:
      type: array
      items:
        $ref: '#/components/schemas/Attachment'
    SendEmailTemplatedBatchRequest:
      properties:
        Messages:
          type: array
          items:
            $ref: '#/components/schemas/EmailWithTemplateRequest'
    SendEmailRequest:
      properties:
        From:
          description: The sender email address. Must have a registered and confirmed Sender Signature.
          type: string
        To:
          description: Recipient email address. Multiple addresses are comma seperated. Max 50.
          type: string
        Cc:
          description: Recipient email address. Multiple addresses are comma seperated. Max 50.
          type: string
        Bcc:
          description: Bcc recipient email address. Multiple addresses are comma seperated. Max 50.
          type: string
        Subject:
          description: Email Subject
          type: string
        Tag:
          description: Email tag that allows you to categorize outgoing emails and get detailed statistics.
          type: string
        HtmlBody:
          description: If no TextBody specified HTML email message
          type: string
        TextBody:
          description: If no HtmlBody specified Plain text email message
          type: string
        ReplyTo:
          description: Reply To override email address. Defaults to the Reply To set in the sender signature.
          type: string
        TrackOpens:
          description: Activate open tracking for this email.
          type: boolean
        TrackLinks:
          description: Replace links in content to enable "click tracking" stats. Default is 'null', which uses the server's LinkTracking setting'.
          type: string
          enum:
          - None
          - HtmlAndText
          - HtmlOnly
          - TextOnly
        Headers:
          $ref: '#/components/schemas/HeaderCollection'
        Attachments:
          $ref: '#/components/schemas/AttachmentCollection'
    Attachment:
      description: An attachment for an email message.
      properties:
        Name:
          type: string
        Content:
          type: string
        ContentType:
          type: string
        ContentID:
          type: string
    SendEmailBatchResponse:
      type: array
      items:
        $ref: '#/components/schemas/SendEmailResponse'