Postmark-PHP

Postmark-PHP is the officially supported PHP library for Postmark.

With Postmark, you can send and receive emails effortlessly.

Requirements

• PHP 8.1, 8.2, 8.3, or 8.4
• Guzzle HTTP client

Security: the Brotli decoder (libbrotli 1.0.3–1.0.9, 1.1.0 and 1.2.0) is affected by CVE-2026-111497. The default Guzzle client this library creates sends no Accept-Encoding header, so the Postmark API answers uncompressed, but it enables all of libcurl's decoders: a Brotli response from a proxy or tampered connection is decoded with your libbrotli when libcurl is built with it. A client you pass in with setClient() uses its own settings. Apply your distro's security update for libbrotli/brotli and curl (upstream fixed in 1.0.10, 1.1.1 and 1.2.1; distros often backport the fix without changing the version).

Getting Started

Check out our wiki to get started using Postmark-PHP now.