Happy Valley

MachineMail vs OpenMail

MachineMail and OpenMail are both team communication tools aimed at developers and small businesses. Both have a free plan.

MachineMail

Email API and MCP server that gives AI agents inboxes of their own

OpenMail

Email inboxes for AI agents, with replies pushed by webhook

PricingFreemium · $9Freemium
Starting price$9/moNot published
Free planYesYes
Free trial——
Built forDevelopers, Small businessesDevelopers, Small businesses
Platformswebweb
Country—LT
Rating——

Choose MachineMail if

Developers building AI agents that need their own email addresses and a safe way to read untrusted inbound mail.

  • Unlimited inboxes are free on every plan
  • Trust layer addresses prompt injection and phishing in email
  • AgentMail-compatible API makes switching a config change

Look elsewhere if: Teams that only need to send transactional or marketing email from an app (Resend).

Choose OpenMail if

Developers building AI agents that need their own email address to receive, thread and answer mail.

  • Built for receiving and replying, not only sending
  • Each inbox has its own sending reputation
  • Free plan needs no credit card

Look elsewhere if: Teams that mainly send marketing or transactional email at high volume (Resend, MachineMail).

MachineMail vs OpenMail pricing

MachineMail

  • Free$03,000 messages/mo (100/day), 1 GB, 1 custom domain, 1 seat
  • Pro$9/mo7,500 inbound, 2,500 outbound, 10 GB, 10 domains, unlimited seats
  • Team$49/mo45,000 inbound, 15,000 outbound, 30 GB, 50 domains, unlimited seats
  • Scale$199/mo200,000 inbound, 65,000 outbound, 150 GB, 250 domains, Slack support

OpenMail

  • Free€0/mo3 inboxes, 3,000 emails/mo (100/day), 3 GB, openmail.sh addresses
  • Pro€9/mo10 inboxes, 10,000 emails, custom domains; then usage-based
  • EnterpriseCustomDedicated sending IPs, SSO, 1-hour SLA, custom DPA

MachineMail · Key features

  • Free inboxes on machinemail.dev or your own domains, ephemeral or permanent
  • Trust report and level on every inbound message
  • Agent-safe text with hidden text and zero-width characters removed
  • Hosted MCP server with 17 tools, including wait_for_message
  • Catch-all domains that create an inbox on first delivery
  • Pods and scoped API keys to separate customers or agents

Cons

  • New service that publishes no team, legal entity or address on its site
  • Free plan caps mail at 100 messages a day
  • No annual pricing listed

OpenMail · Key features

  • One API call or CLI command creates a dedicated agent inbox
  • Inbound mail delivered in real time over webhook or WebSocket
  • Full email threading so agents reply in the same conversation
  • PDF, CSV and image attachments parsed into plain text (extra cost)
  • Allow and block rules per address or domain
  • Custom domains with DKIM, SPF and DMARC on Pro

Cons

  • Pricing page mixes $9 and €9; overage rates are in euros
  • Free plan caps sending at 100 emails a day
  • Free plan appends a "Sent with OpenMail" footer

MachineMail vs OpenMail: FAQ

Do MachineMail and OpenMail have a free plan?

Yes, both MachineMail and OpenMail have a free plan; paid plans add more usage and features.

Not sure yet?