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Postmark alternative for transactional email
Postmark-class job: transactional mail that has to land. SuperSend TX gives you a modern API on infrastructure we operate, with Pool and Dedicated tiers.
- Transactional only
- POST /emails
- Owned Pool · Dedicated
At a glance
Transactional focus, modern DX, owned pipe
Both products take critical mail seriously. SuperSend TX pairs that focus with npm + curl ergonomics and a clear path to Dedicated servers.
| Attribute | Postmark | SuperSend TX |
|---|---|---|
| Focus | Transactional | Transactional only |
| API | POST /email | POST /emails |
| Auth | Server token | Bearer stx_… |
| Infra story | Postmark-operated | Owned transactional network; Dedicated available |
| Entry paid plan | Postmark plans | Pro from $20/mo · Scale volume slider |
Why teams look here
Short path to first production send
Keep transactional mail off cold reputation, with a volume ladder that is easy to explain to finance.
npm + curl DX
Official SDK, CLI, and a flat POST /emails body so engineering can cut over without a redesign.
Clear volume ladder
Sandbox → Pro → Scale with a transparent overage curve — Dedicated when isolation matters more than volume.
Ops that know mail
From the team behind SuperSend outbound — transactional stays on its own reputation surface.
Dedicated when needed
Managed servers and IPs for your workspace. Same API as Pool — no rewrite when you isolate.
Migration
Map fields and cut over webhooks
Postmark tokens become stx_ keys. Payloads flatten. Event handlers re-subscribe to signed SuperSend TX webhooks.
- 1
Create a key
Issue a Bearer stx_… key and verify the domain you send from.
- 2
Swap the client
Point HTTP or the supersendtx SDK at api.supersendtx.com.
- 3
Map fields
Use the Postmark migration guide for field mapping.
- 4
Reconnect webhooks
Subscribe to delivered, bounced, complained, and the rest with whsec_… signing.
- Transactional-only Pool — no marketing or cold mail on the same pipe
- Inbound, templates, automations, SMTP, SDK, CLI, and MCP included
- Dedicated servers and listed IPs when compliance asks for isolation
Send transactional mail on SuperSend TX
Start on Sandbox, move to Pool for production, upgrade to Dedicated for managed servers and IPs.