Posthorn: A self-hosted email gateway bridging apps and transactional mail providers
By
craigmccaskill
Kettled twice. Extra chewy, extra trustworthy.
Summary
Posthorn is a self-hosted, open-source email gateway that acts as a unified outbound mail layer between self-hosted applications and transactional email providers (Postmark, Resend, Mailgun, AWS SES, or outbound-SMTP). It supports three ingress shapes (HTTP form, HTTP API, SMTP) and runs as a single Go binary with a single TOML configuration file, deployable via Docker. The project addresses the need for self-hosted operators to avoid running their own mail servers while maintaining reliable email delivery through established transactional providers.
Key quotes
· 3 pulledNobody wants to run a mail server in 2026.
Self-hosted operators use Postmark, Resend, Mailgun, or AWS SES because they're cheap, they handle deliverability properly.
One gateway between every app you self-host and the transactional mail provider you've already picked.
You might also wanna read
NVIDIA Announces "Hack for Impact" London Event for Autonomous AI Agent Development
NVIDIA is hosting a "Hack for Impact" event in London, challenging participants to build autonomous agentic applications using open-source m
luma.com·52m ago
Four practical steps to control Azure Foundry token costs for agentic AI workloads
This article provides practical guidance on controlling token costs in Microsoft Azure Foundry, particularly for agentic AI workloads where
purplefrogsystems.com·2h ago
MerLean-Prover: A Recursive Agent Harness for Lean 4 Theorem Proving Outperforms Baselines
MerLean-Prover is an end-to-end Lean4 theorem prover that replaces 'sorry' declarations with kernel-checkable proofs using three agent types
arxiv.org·2h ago
Why small pull request policies can backfire on software quality
The article critiques a common software engineering policy that limits pull requests (PRs) to small sizes (e.g., 500 lines, few files). Whil
apenwarr.ca·4h ago
How Anthropic contains Claude's expanding access across its products
Anthropic describes how it has evolved its approach to granting Claude, its AI assistant, increasingly broad access to internal systems over
anthropic.com·5h ago
Testing Cursor's Jira integration: How ticket quality affects AI agent performance
Cursor launched a Jira integration that lets developers assign tickets directly to an AI agent, eliminating context switching. The author te
bit.ly·5h ago