Side by side
Posta vs Postmark
Both stand on transactional email services. Which one you can start free with, which one lets you read the code, and what each costs once you pay.
Choose Posta if your team can run email infrastructure and wants API sending, SMTP relay, inbound mail, templates, and webhooks in one platform. Its free AGPL-3.0 license and Docker Compose startup option are useful for self-hosting. Teams relying on web forms should account for the disabled default and submission limits.
Visit Posta
Postmark offers application email delivery, tracking, and inbound processing with a permanent but limited free tier. Compare paid-plan email allowances and overage rates, and account for the stated message size and recipient limits.
Visit PostmarkThe facts
| Posta | Postmark | |
|---|---|---|
| Free plan | Yes | Yes |
| Open source | Not published | Not published |
| Runs on | API, Self-hosted, Web | API, Web |
| Lowest paid plan | Free or on request | See the plans |
| Plans published | 1 | 8 |
| Maker | Not published | Postmark |
| Website | goposta.dev | postmarkapp.com |
| On transactional email services | #6 of 41 | #2 of 41 |
Posta: what it does well
- Self-hosted and free under the AGPL-3.0 license.
- Handles transactional, batch, and templated email sends.
- Supports inbound email, forwarding, and real-time SSE notifications.
- Templates include versioning, localization, visual editing, and preview.
- Webhooks support event filters, HMAC signing, retries, and delivery tracking.
What to know first
- Requires deployment on customer infrastructure.
- Web form messages are disabled by default.
- Default web form limits are 200 submissions per form per hour and 1,000 per workspace per day.
Postmark: what it does well
- Free plan never expires and allows 100 emails monthly.
- Supports REST API, SMTP, and multi-region SMTP routing.
- Separates transactional and broadcast email infrastructure.
- Inbound email can be delivered to a webhook as JSON.
- Customer success support is included without a premium fee.
What to know first
- The free plan does not allow overages.
- Unused emails do not carry into the next billing period.
- Annual plans are not currently offered.
- Email messages are limited to 10 MB and 50 recipients.
Alternatives to Posta Alternatives to Postmark The whole list