Agent Skills

Use when working with Postmark email platform - routes to specific sub-skills for sending emails, processing inbound email, managing templates, or configuring webhooks.

Install

npx skills add https://github.com/activecampaign/postmark-skills --skill postmark
SKILL.md

Postmark Skills

Postmark is a transactional email platform built for developers, with 15+ years of deliverability expertise. These skills teach AI agents how to use the Postmark API effectively.

Sub-Skills

Feature Skill Use When
Sending emails postmark-send-email Sending transactional or broadcast emails — single, batch, bulk, or with templates
Inbound processing postmark-inbound Processing incoming emails via webhooks, building reply-by-email, email-to-ticket, or document extraction
Template management postmark-templates Creating, editing, or sending with Postmark's server-side Handlebars templates and layouts
Webhooks postmark-webhooks Setting up outbound webhooks for delivery, bounce, open, click, spam complaint, and subscription change events — including endpoint verification, per-webhook statistics, and retry behavior
Best practices postmark-email-best-practices Deliverability setup, compliance (CAN-SPAM/GDPR/CASL), email design, list management, testing, and sending reliability

Outbound and inbound webhooks are different systems

postmark-webhooks covers outbound event webhooks; postmark-inbound covers inbound email webhooks. They run on separate infrastructure and have different retry schedules — do not apply one to the other:

Outbound webhooks (postmark-webhooks) Inbound webhooks (postmark-inbound)
Retries Up to 9 retries over ~72 minutes (3 standard + 6 backoff) Up to 10 retries over ~10.5 hours
Retried on 5xx, 408, 429, network timeouts only — every other 4xx is permanent Any non-200 response

Endpoint verification and per-webhook statistics are outbound features — see postmark-webhooks.

Quick Routing

  • "Send an email" → postmark-send-email
  • "Send a batch of emails" → postmark-send-email
  • "Send using a template" → postmark-send-email (template section) or postmark-templates (to create/manage templates)
  • "Handle incoming email" → postmark-inbound
  • "Process inbound webhooks" → postmark-inbound
  • "Create an email template" → postmark-templates
  • "Track deliveries/bounces/opens" → postmark-webhooks
  • "Set up bounce handling" → postmark-webhooks
  • "Verify a webhook endpoint" / "my webhook is unverified" → postmark-webhooks
  • "Webhook statistics / failure rate / why is my webhook paused" → postmark-webhooks
  • "Webhook retries" → postmark-webhooks (outbound events) or postmark-inbound (inbound email)
  • "Set up SPF/DKIM/DMARC" → postmark-email-best-practices
  • "Email compliance / GDPR / CAN-SPAM" → postmark-email-best-practices
  • "Domain warm-up" → postmark-email-best-practices
  • "List hygiene / suppression management" → postmark-email-best-practices
  • "Design a transactional email" → postmark-email-best-practices
  • "Test email safely" → postmark-email-best-practices

Common Setup

Authentication

Postmark uses two types of API tokens:

Token Header Scope
Server Token X-Postmark-Server-Token Sending emails, templates, bounces, webhooks, message streams
Account Token X-Postmark-Account-Token Managing servers, domains, sender signatures

Get your Server API Token from Postmark Servers.

SDK Installation

Detect the project language and install the appropriate SDK:

File Language Install Command
package.json Node.js / TypeScript npm install postmark
requirements.txt / pyproject.toml Python pip install postmarker
Gemfile Ruby gem install postmark
composer.json PHP composer require wildbit/postmark-php
*.csproj / *.sln .NET dotnet add package Postmark

Message Streams

Postmark separates email by intent into Message Streams:

Stream Value Purpose
Transactional outbound 1:1 triggered emails (welcome, password reset, receipts) — default
Broadcast broadcast Marketing, newsletters, announcements

Never mix transactional and broadcast email in the same stream — it damages deliverability.

Resources

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