OpenMail vs Postman
OpenMail and Postman are both developer tools tools aimed at developers and small businesses. Both have a free plan.
Email inboxes for AI agents, with replies pushed by webhook
API platform for testing, mocking, documenting and sharing APIs
| Pricing | Freemium | Freemium · $9 |
| Starting price | Not published | $9/mo |
| Free plan | Yes | Yes |
| Free trial | — | — |
| Built for | Developers, Small businesses | Developers, Small businesses, Enterprise |
| Platforms | web | web, macos, windows, linux |
| Country | LT | US · 2014 |
| Rating | — | — |
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).
Choose Postman if
Development teams that want a shared, full-featured workspace for testing, mocking and documenting APIs.
- Industry standard; many API vendors ship ready Postman collections
- Testing, mocking, docs and monitoring in a single tool
- Capable Free plan for solo developers
Look elsewhere if: Developers who want a lightweight Git-native client or just a docs portal (Bruno, Insomnia, ReadMe, Scalar).
OpenMail vs Postman pricing
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
Postman
- Free$01 user; collections, mock servers, up to 5 integrations
- Solo$9/moBilled annually; 1 user, 400 AI credits/mo
- Team$19/user/moBilled annually; unlimited users, 400 AI credits/user
- EnterpriseCustomGovernance, 800 pooled AI credits/user, 100 integrations
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
Postman · Key features
- Collections with pre-request scripts, tests and environment variables
- Requests for REST, GraphQL, gRPC, WebSocket and MQTT APIs
- Mock servers that simulate endpoints before the backend exists
- Scheduled monitors for uptime and response checks
- Collection runner and Postman CLI for CI/CD pipelines
- Spec Hub and native Git sync for API definitions
Cons
- Free plan no longer allows team collaboration
- Heavy desktop app and a cloud account needed for most features
- Collections live in a proprietary format, not plain files in your repo
OpenMail vs Postman: FAQ
Do OpenMail and Postman have a free plan?
Yes, both OpenMail and Postman have a free plan; paid plans add more usage and features.