Send and track transactional email with templates and bounce tracking via the Postmark API.

Postmark

Send and track transactional email through the Postmark API. Send raw or template-based emails, list bounces, and pull delivery and outbound statistics.

Base URL: https://api.postmarkapp.com
Auth: X-Postmark-Server-Token: <apiKey> header (Postmark Server API Token)
Standard library only (Python urllib/json) — no external dependencies. Response bodies are capped at 5 MB.

Operations

Operation	Method / Endpoint	Purpose
`send-email`	`POST /email`	Send a single transactional email (HTML and/or text).
`send-email-template`	`POST /email/withTemplate`	Send an email rendered from a Postmark template.
`list-bounces`	`GET /bounces`	List bounced messages, optionally filtered by type/recipient.
`get-delivery-stats`	`GET /deliverystats`	Summary of bounce counts and inactive addresses.
`get-outbound-stats`	`GET /stats/outbound`	Aggregate outbound send statistics.

apiKey setup

Sign in to the Postmark dashboard.
Open your Server, then go to the API Tokens tab.
Copy the Server API Token and pass it as the apiKey input. The tool sends it as the X-Postmark-Server-Token header.
For testing without sending real mail, use the special token value POSTMARK_API_TEST.

Note: the from address must be a verified Sender Signature (or be on a verified domain) in your Postmark account, or the send will be rejected.

Inputs

apiKey (required) — Postmark Server API Token.
operation (required) — one of the operations above.
from, to, subject, htmlBody, textBody, cc, bcc, replyTo, tag, messageStream — for send-email (at least one of htmlBody/textBody is required).
from, to, templateId or templateAlias, templateModel (JSON), messageStream — for send-email-template.
type, recipient, count, offset — optional filters for list-bounces.
fromDate, toDate, tag — optional filters for get-outbound-stats.

Output

Every call prints a single JSON envelope:

{ "result": "<response body as JSON string>", "status": "<http status code>" }

On failure it prints { "error": "...", "status": "0", "result": "" } and exits non-zero, marking the step as failed.

Examples

Send a transactional email

operation:  send-email
apiKey:     <your-server-token>
from:       [email protected]
to:         [email protected]
subject:    Your receipt
textBody:   Thanks for your purchase!
tag:        receipt

A successful send returns { "MessageID": "...", "SubmittedAt": "...", "ErrorCode": 0, "Message": "OK", "To": "[email protected]" }.

Send via a template

operation:      send-email-template
apiKey:         <your-server-token>
from:           [email protected]
to:             [email protected]
templateAlias:  welcome
templateModel:  {"name":"Sam","product_url":"https://app.example.com"}

List recent hard bounces

operation:  list-bounces
apiKey:     <your-server-token>
type:       HardBounce
count:      50

Check delivery stats

operation:  get-delivery-stats
apiKey:     <your-server-token>