OpenSend vs Postmark
OpenSend
opensend.namuh.co
Postmark
postmarkapp.comSide by side
| Figure | OpenSend | Postmark |
|---|---|---|
| Price from | $10/mo | $5/mo |
| Free plan | — | Yes |
| Free trial | — | Yes |
| Open source | — | — |
| Web | Yes | Yes |
| API | Yes | Yes |
| Self-hosted | Yes | — |
| Plans published | 5 | 8 |
| Spec score · Email APIs | 7.3 (#25) | 8.6 (#6) |
| Integrations | The self-hosting guide documents AWS SES/SNS, PostgreSQL, Redis, S3, Cloudflare DNS automation, and Google OAuth configuration. | Official integrations include Slack, Zapier, Stripe, WordPress, Supabase, Bubble, Craft CMS, Netlify, and Gravity Forms. |
| Security | Dashboard and API routes are tenant-scoped through Better Auth organizations and server-side ownership checks. | Postmark supports TLS and HTTPS, DKIM, SPF, DMARC, two-factor authentication, API permission controls, penetration testing, and DDoS protection. |
| Support | The Free and Lite plans include community support, Starter has email support with a 48-hour response target, and Growth has priority support with a 12-hour target. | Postmark offers support by email, live chat, and one-on-one calls and reports a 95% customer happiness rating. |
Plans
OpenSend
- Lite$10 a month
- Starter$19 a month
- Growth$99 a month
- FreePrice not published
- ScalePriced on request
Postmark
- FreeFree
- Basic$15 a month
- Pro$16.50 a month
- Platform$18 a month
- Custom activity retention$5 a month
- DMARC monitoring$14 a month
- Dedicated IP$50 a month
- High-volume plansPriced on request
In their own words
OpenSend
OpenSend has no write-up on Specifiction yet; its figures are above.
Postmark
Postmark delivers and tracks application email as an alternative to SMTP or Sendmail. It separates transactional and broadcast messages into different Message Streams and IP infrastructure. Developers can send through REST API, SMTP, or multi-region SMTP routing, with official libraries for Node.js, Python, Rails, Ruby, PHP, and.NET. Inbound messages can be converted to JSON and sent to a webhook URL. Tracking includes delivery, bounces, spam, opens, and links, with event webhooks. Editable responsive templates cover transactional messages such as password resets, receipts, and invitations. The free Developer plan costs nothing, provides 100 emails per month, permits no overages, and does not expire. Basic starts at $15 a month for 10,000 emails per month; extra emails cost $1.80 per 1,000 and are calculated at the end of the billing cycle. Unused emails do not roll over. Postmark lists API and web access. Its iOS app was sunset in June 2025 and is no longer supported.