postmark-send-email

postmark-send-email is a skill for Claude Code, Codex from ActiveCampaign/postmark-skills. It costs 43 tokens per session (2,610 once invoked), scanned A, original, MIT.

A skill for sending transactional or broadcast email through Postmark, an email delivery service. It supports individual, batch, bulk, and template-based messages, including attachments and tracking.

In plain words
What is it for?
Use it to send one email, send up to 500 different or template-based emails in a batch, send bulk campaigns, add attachments, and use server-side templates.
Why use it?
It removes the need to choose and assemble Postmark’s different email requests manually. It also separates one-to-one triggered messages from broadcast campaigns using message streams.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it to send one email, send up to 500 different or template-based emails in a batch, send bulk campaigns, add attachments, and use server-side templates.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/activecampaign/postmark-skills/postmark-send-email
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add ActiveCampaign/postmark-skills --skill postmark-send-email
Clone the repo
git clone --depth 1 https://github.com/ActiveCampaign/postmark-skills

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for postmark-send-email

README.md
[![agentmods](https://agentmods.dev/badge/skills/activecampaign/postmark-skills/postmark-send-email.svg)](https://agentmods.dev/skills/activecampaign/postmark-skills/postmark-send-email)
Your own site
<a href="https://agentmods.dev/skills/activecampaign/postmark-skills/postmark-send-email"><img src="https://agentmods.dev/badge/skills/activecampaign/postmark-skills/postmark-send-email.svg" alt="Measured on agentmods" height="20"></a>
Per session 43 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,610 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 3 findings, up to medium

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • medium Data Exfiltration · line 57
    Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.
    Fix: Verify the destination URL is trusted and necessary. Remove or replace with documented APIs. Ensure no secrets, tokens, or PII are transmitted.
  • medium Data Exfiltration · line 106
    Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.
    Fix: Verify the destination URL is trusted and necessary. Remove or replace with documented APIs. Ensure no secrets, tokens, or PII are transmitted.
  • medium Data Exfiltration · line 142
    Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.
    Fix: Verify the destination URL is trusted and necessary. Remove or replace with documented APIs. Ensure no secrets, tokens, or PII are transmitted.
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00043 $0.02610
Opus 5 $0.00022 $0.01305
Sonnet 5 $0.00009 $0.00522
Haiku 4.5 $0.00004 $0.00261

Measured 8d ago against content hash b2debe5cbf59, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

postmark-send-email scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 8d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

postmark-send-email/SKILL.md · 279 lines

How it starts

The opening of the file, as written. The whole thing — 279 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Send Email with Postmark

Overview

Postmark provides multiple endpoints for sending emails:

Approach Endpoint Use Case Limits
Single POST /email Individual transactional emails 1 email, 10 MB payload including attachments
Batch POST /email/batch Up to 500 emails in one request 500 emails, 50 MB payload including attachments
Template POST /email/withTemplate Dynamic content with server-side templates 1 email, 10 MB payload including attachments
Batch Template POST /email/batchWithTemplates Bulk templated emails 500 emails, 50 MB payload including attachments
Bulk POST /email/bulk Broadcast stream campaigns No fixed recipient cap, 50 MB payload including attachments

Choose batch when: sending 2+ distinct emails at once, performance matters, or attachments are needed. Choose single when: sending one email or real-time per-message error handling is needed.

Message Streams (CRITICAL)

Postmark separates emails by intent. Always specify MessageStream:

Stream Value Purpose SMTP Endpoint
Transactional outbound 1:1 triggered emails (default) smtp.postmarkapp.com
Broadcast broadcast Marketing, newsletters smtp-broadcasts.postmarkapp.com

Never mix transactional and broadcast in the same stream — it damages deliverability. Servers can have up to 10 message streams.

Quick Start

  1. Get API Token from your Postmark server settings
  2. Verify sender domain or email address
  3. Install SDK — see references/installation.md
  4. Choose endpoint based on the decision matrix above

Authentication

All API requests require the Server API Token:

X-Postmark-Server-Token: your-server-token-here

Store the token in POSTMARK_SERVER_TOKEN. For testing without sending, use POSTMARK_API_TEST as the token value.

Read the full file on GitHub · 279 lines

Files

What ships with it

6 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 8d ago First seen · 279 lines · 43 tokens per session scan A b2debe5cbf59

Subscribe to this mod's changes

postmark-send-email is a skill published in the GitHub repository ActiveCampaign/postmark-skills (45 stars, last pushed 20d ago), licensed MIT. It adds 43 tokens to every session and 2,610 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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