Source

API documentation — Postmark

Checked for Postmark on 1 Nov 2026

Page: https://postmarkapp.com/developer
Checked: 1 Nov 2026, 09:51 UTC
How we may use it: Public page, crawling permitted

Technical details

type: page
http status: 200
content hash: sha256:6cceabd97341bb229d8e154c3c2cc3112462d4e71069baaa4393de13e7e0ecb9
permission: robots_ok
screenshot: Screenshot on file (internal exhibit, not published)

Cited by

Facts read from this source

Rest API Report an error

“Every HTTP request in Postmark’s REST API, in detail.”
Max email size Report an error

“10 MB max per email. Content, headers, and attachments combined.”
Max recipients Report an error

“50 recipients per message, combined. That's your total across To, CC, and BCC”
Message streams separation Report an error

“We send transactional and broadcast messages travel on different IP infrastructure, so your most critical emails make it to the inbox.”
Official libraries Report an error

“TypeScript Node.js Python Ruby Rails PHP .NET Java”
Smtp service Report an error

“Sending email with SMTP”
Inbound processing Report an error

“What is inbound processing?”
Open tracking Report an error

“Tracking opens”
Ip allowlisting Report an error

“IP Allowlisting”
Webhooks Report an error

“Webhooks overview Delivery webhook Bounce webhook Spam complaint webhook Open tracking webhook Click webhook Subscription change webhook Inbound webhook”
AI tooling Report an error

“Agent Skills for Claude Code, Cursor, and Copilot; an llms.txt for context; the MCP server; and the CLI.”
API endpoints Report an error

“Overview Email Bulk Bounce Templates Server Servers Message Streams Messages Domains Sender signatures Stats Triggers: Inbound rules Webhooks Suppressions Data Removal”
Templates API Report an error

“Templates API”
Bounce API Report an error

“Bounce API”
Sandbox mode Report an error

“Sandbox mode”
EU data protection Report an error

“EU Data Protection”

2 facts read from this page are not shown because they could not be confirmed on the page as captured.

Scores citing this record

The Agency Lead Sending API, SMTP & developer experience
The Data Protection Officer Sending API, SMTP & developer experience
The Shop Operator Sending API, SMTP & developer experience
The Platform Engineer Sending API, SMTP & developer experience
The Platform Engineer Message logs, events & webhooks
The SaaS Developer Sending API, SMTP & developer experience
The SaaS Developer Reliability, accounts & support
The Skeptic Sending API, SMTP & developer experience