Show HN: Email inbox for your OpenClaw agent
mailboxkit.comHey HN,
I built MailboxKit because I kept running into the same problem: AI agents need email but existing APIs aren't designed for them.
The typical flow for an agent is: get an email address, send messages, receive replies, and handle threading — all via API, without a human setting things up. Most email services require manual domain verification, complex OAuth, or aren't built for programmatic access from the start.
MailboxKit lets an agent self-register and start sending/receiving in a single API call:
``` POST /api/v1/register {"name": "My Agent", "owner_email": "you@example.com"}
→ {"api_key": "mbk_...", "email": "abc123@agent.mailboxkit.com", "inbox_id": '19999d'} ```
That's it. The agent now has a real email address, can send and receive, and gets inbound messages via webhooks. Threading, read/unread tracking, attachments, and custom domains all work out of the box.
The API docs double as an LLM-readable skill file (mailboxkit.com/skill.md) so agents using tool-use can discover and learn the API themselves.
Currently used by a handful of agents doing customer support, research, and outreach. Would love feedback from anyone building agent infrastructure. The single API call to get an email address up and running is a nice DX touch. We've seen at Nylas how much friction OAuth flows and domain verification add when all you want is programmatic email access. Curious about deliverability on the shared domain — have you run into issues with @agent.mailboxkit.com landing in spam? In our experience, shared sending domains hit reputation problems fast once multiple tenants are sending from them, especially for outreach use cases. The LLM-readable skill file idea is clever. We've been doing something similar with llms.txt for AI discoverability. We also just shipped an OpenClaw plugin for Nylas (https://www.npmjs.com/package/@nylas/openclaw-nylas-plugin) that gives agents email, calendar, and contacts access out of the box — different approach since it connects to real user mailboxes rather than creating new addresses, but solves the same "agents need email" problem.