OpenMail vs AgentMail: what changes at scale

OpenMail vs AgentMail · Updated September 2026Both give agents their own inbox. At scale, the questions are: whose reputation do your tenants share, and where does the data live?

Start For Free →See the code ↓

Where they differ

FeatureOpenMailAgentMail
Reputationper inboxper domain (shared on free)
Inbound eventbody + parsed attachmentsbody + HTML; attachments separate
Tenant isolationdata + reputationdata only
Data residencyEU, every planUS
First paidEUR 9/moUSD 20/mo
Extra inboxEUR 1/monot published
SOC 2in progressStartup tier
SDKsREST + CLI, no SDK yetPython, TypeScript, CLI

Reputation isolation

One tenant sends five thousand cold emails. Mailbox providers notice. What happens to your other tenants?

AgentMail

Pods isolate data. But reputation is per sending domain — one tenant's complaints mark every address on the shared domain.

OpenMail

Reputation is per inbox. The bad actor gets throttled; the agent next door keeps delivering normally.

Pricing

OpenMail ProEUR 9/mo for 10 inboxes, then EUR 1 per inbox
AgentMail DevUSD 20/mo for 10 inboxes; Startup USD 200/mo for 150
At scaleOpenMail grows EUR 1 per inbox; AgentMail add-on pricing not published

Migration

InboxesCreate by API; live immediately
DomainsAdd, publish DNS, verify. Cut over per domain.
ThreadsExport first; history does not transfer
Helpsupport@openmail.to

Choose OpenMail if

Your tenants need to be sealed from each other’s reputation

You want parsed attachments in the inbound event, not a second fetch

EU data residency on every plan, no enterprise contract

You’re counting inboxes in the hundreds

Three calls

1. Create the inbox.

bash
curl -X POST https://api.openmail.sh/v1/inboxes \
  -H "Authorization: Bearer $OPENMAIL_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"mailboxName": "assistant", "displayName": "Acme Assistant", "podId": "cust_acme"}'

2. Send. The inbox-scoped key can only send from this one inbox.

bash
curl -X POST https://api.openmail.sh/v1/inboxes/inbox_123abc/send \
  -H "Authorization: Bearer $OPENMAIL_AGENT_KEY" \
  -H "Idempotency-Key: $(uuidgen)" \
  -H "Content-Type: application/json" \
  -d '{"to": "customer@example.com", "subject": "Your order", "body": "Shipped today, tracking below."}'

3. Reply in thread.

bash
curl -X POST https://api.openmail.sh/v1/inboxes/inbox_123abc/send \
  -H "Authorization: Bearer $OPENMAIL_AGENT_KEY" \
  -H "Content-Type: application/json" \
  -d '{"to": "customer@example.com", "body": "Delivered. Anything else?", "threadId": "thr_xyz"}'

Full walkthrough: How to give your AI agent its own email address

Where AgentMail has the edge

SOC 2 report on Startup tier. Python and TypeScript SDKs. Public MCP server. Replit integration. Cross-org thread queries. If your buyer needs SOC 2 this quarter, AgentMail has it today.

Building an agent startup?

€500 in usage credit for pre-seed, seed and bootstrapped teams. Six months on Pro.

Apply now →

Frequently asked questions.

Both give agents their own inboxes with pods and scoped keys. OpenMail adds per-inbox sending reputation, parsed attachments in the inbound event, and EU data residency on every plan. AgentMail has SOC 2 today and a longer integrations list.

Not on self-serve plans. AgentMail operates from San Francisco. OpenMail keeps data in the EU on every plan, free included.

Both start free with 3 inboxes. OpenMail Pro is EUR 9/mo for 10 inboxes, then EUR 1 per inbox. AgentMail Developer is USD 20/mo for 10; Startup USD 200/mo for 150. Add-on pricing beyond tiers is not published.

Yes. Create inboxes and pods by API, cut over custom domains one at a time via DNS, export thread history before switching.

Plugins for OpenClaw and Hermes Agent, a Claude Code skill, LangChain, CrewAI and Vercel AI SDK guides, and a CLI.

Every AI agent deserves its own inbox.

Start building today.

Start For Free →

3 inboxes, 3,000 emails a month, no card required