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Postmark email API

Transactional email API. Verify your domain (DKIM TXT and Return-Path CNAME), get a server API token, and request account approval before sending to outside recipients.

Researched · not yet run liveLast researched 25 October 2026 · Postmark · provider site

Researched, not yet run live. Built from the provider’s official pages (linked below). A person hasn’t walked this flow end to end yet, so check each step against the source.
Do this with verapliJSON for agents

Have ready

  • A domain you control with access to its DNS settings
  • DNS access for the sending domain · DKIM and Return-Path records are added at your DNS host. [1]Needed for: Add the DKIM and Return-Path records
  • Examples of the emails you plan to send · Postmark reviews accounts for approval to protect its sending reputation. [2]Needed for: Request account approval

Steps

Steps marked “human step” are ones only you can do: verapli never signs in, submits, pays or accepts terms for you.

  1. Sign in or create a Postmark account

    Sign in to Postmark. If you have no account yet, you create it yourself; verapli does not create accounts.

    • Guided by hand
    • Human step: You sign in

    Where: https://account.postmarkapp.com/login

  2. Add your sending domain

    On the Sender Signatures page, add your domain so you can send from any address on it.

    • Guided by hand
    • Human step: You press submit
    • After: Sign in or create a Postmark account

  3. Add the DKIM and Return-Path records

    Add the DKIM TXT record with the hostname and value Postmark shows, and a CNAME at pm_bounces (default) pointing to pm.mtasv.net. Click Verify if they do not verify on their own.

    • Guided by hand
    • After: Add your sending domain
    The provider says
    DKIM and Return-Path show as verified within 48 hours of adding the records. [1]
    If something goes wrong (1)
    • Record not verified automatically: Use the Verify button next to the record to start a manual check. [1]

  4. Copy the server API token

    Open your server's API Tokens tab and copy the Server API token (sent in the X-Postmark-Server-Token header).

    • Guided by hand
    • After: Sign in or create a Postmark account

    verapli captures POSTMARK_SERVER_TOKEN here by plain code: encrypted in your browser, never shown to AI.

  5. Request account approval

    The Account Owner submits the account for approval. Until approved you can only send to domains you added and verified (or the test@blackhole.postmarkapp.com sink), and link tracking is off.

    • Guided by hand
    • Human step: The provider reviews it
    • After: Add the DKIM and Return-Path records
    The provider says
    Review is completed in less than 24 hours on weekdays and a little longer at weekends. [2]
    If something goes wrong (1)
    • Account not approved: Email support@postmarkapp.com with examples of the emails you want to send. [2]

Terms and gotchas

Plain-English summary, not legal advice. Each card links its source.

Can cost moneyThe rules say

Approval gate

Until Postmark approves the account you cannot send to addresses outside your verified domains. [2]

What you end up with

Env varSecretFormatWhat it is
POSTMARK_SERVER_TOKENsecretPostmark Server API token (X-Postmark-Server-Token). Postmark's docs name no env var; this name is a verapli convention.

Pricing

  • Free tier: Developer plan, 100 emails/month, no overages, does not expire.
  • Costs: Basic from $15/month for 10,000 emails (extra $1.80 per 1,000); Pro $16.50 and Platform $18.00 starting tiers.

Source [4]

For agents

The same entry as JSON: /api/v1/entries/postmark/email · requirements /api/v1/requirements/postmark/email · terms /api/v1/terms/postmark/email.

Remote MCP (read-only, no auth)
claude mcp add --transport http verapli https://verapli.com/mcp

> "What do I need for Postmark email API, and how long will it take?"
  → tools/call requirements { "provider_id": "postmark/email" }

Sources

  1. Postmark support - How do I verify a domain? DKIM TXT record from Sender Signatures > DNS Settings; Return-Path CNAME default hostname pm_bounces pointing to pm.mtasv.net; both verify within 48 hours; Verify button for a manual check; domain verification lets you send from any address on the domain · accessed 25 October 2026 · official
  2. Postmark support - How does the account approval process work? Unapproved accounts cannot send outside added and verified domains; sink address test@blackhole.postmarkapp.com; link tracking unavailable until approval; only Account Owner submits approval; review under 24 hours on weekdays, longer on weekends · accessed 25 October 2026 · official
  3. Postmark API overview X-Postmark-Server-Token and X-Postmark-Account-Token headers; server token on the server's API Tokens tab; POSTMARK_API_TEST test value; no env var names documented · accessed 25 October 2026 · official
  4. Postmark pricing Developer plan 100 emails/month free, no overages, does not expire; Basic $15/mo for 10,000 emails · accessed 25 October 2026 · official

Provider rules change. This page is generated from verapli registry version 2026.1025.316; spotted something out of date? Tell us. Postmark is not affiliated with verapli.