For critical transactional email.
Purpose-built infrastructure for mail that has to arrive.
curl -X POST \
https://api.supersendtx.com/emails \
-H "Authorization: Bearer stx_…" \
-H "Content-Type: application/json" \
-d '{
"from": "[email protected]",
"to": "[email protected]",
"subject": "Reset your password",
"html": "<p>Click to reset.</p>"
}'{ "id": "msg_4f9c1a7e…", "status": "queued" }
Signed webhooks fire on every state change — bounced, complained, opened, and clicked included.
Infrastructure
Critical mail shouldn't share fate with strangers.
Start on a transactional-only Pool. Upgrade to Dedicated when you need your own servers and IPs, built and managed by us. Same API either way.
Pool
Shared transactional lane — isolated reputation
- Transactional senders only — no marketing noise
- Marketing never shares this pipe
- Warmed, monitored, and operated by us
Dedicated
Your own servers and IPs
- Provisioned for your workspace alone
- IPs listed in the dashboard for allowlists
- Built, warmed, and managed by us
Same API either way — moving to Dedicated does not change your send code.
Isolated transactional pipe
Pool carries critical transactional mail from paying customers. No free-tier noise — and marketing never shares this reputation.
See the platform →Built for deliverability
Warmup, bounce handling, complaints, suppressions, and open/click signals are managed so critical mail stays healthy.
Deliverability docs →Dedicated when you need it
Your own mail server and IPs. We build, warm, and manage them. Same API as Pool.
Compare plans →Domains & authentication
SPF, DKIM, DMARC, and return-path setup — including one-click DNS apply for Cloudflare and GoDaddy.
Domain docs →You ship the product. We keep critical mail deliverable.
How the send path reacts to providers →Platform
A full developer platform, not just a send endpoint.
Integrate once with HTTP, an SDK in your language, the CLI, SMTP, or MCP. Every capability is on every plan.
Send API
POST /emails with batch, schedule, cancel, resend, idempotency, attachments, and verified domains.
See all features →Receive & reply
Inbound on your domain, email.received webhooks, and an Inbound dashboard — no second vendor for replies.
Inbound email →Webhooks & events
Signed endpoints (whsec_…). Delivered, bounced, complained, opened, clicked, suppressed, scheduled, and more.
Webhook docs →Templates
Visual block editor with versioned publish, {{variables}}, and a starter gallery. Send by alias from any SDK; push HTML from git with the CLI.
Templates →Automations
POST /events triggers multi-step flows: send email, conditions, and run history in the dashboard.
Automations →SMTP relay
smtp.supersendtx.com:587 for Supabase, Clerk, and legacy SMTP clients — same account rules as HTTP.
SMTP →SDKs, CLI & MCP
Official SDKs for Node, Python, PHP, Ruby, and Go — plus Laravel, a CLI, hosted MCP with OAuth, and Agent Skills.
Agents & MCP →Ops & migrate
Suppressions, deliverability insights, Cloudflare/GoDaddy DNS apply, and migrations from Resend, Postmark, SES, and SendGrid.
See all features →Example send
curl -X POST https://api.supersendtx.com/emails \
-H "Authorization: Bearer stx_…" \
-H "Content-Type: application/json" \
-d '{
"from": "[email protected]",
"to": "[email protected]",
"subject": "Reset your password",
"html": "<p>Click to reset.</p>"
}'- · SDKs: Node, Python, PHP, Ruby, Go (+ Laravel)
- · tx.emails.send({ … }) in every language
- · CLI: npx -y --package=supersendtx-cli -- supersendtx emails send
- · SMTP: smtp.supersendtx.com:587
- · Hosted MCP + Agent Skills for agents
Observability
Know what happened to every message.
Track delivery events, enforce suppressions, receive inbound mail, and see deliverability signals in one place.
Pricing
Pricing lives on Ranla now.
Same transactional email infrastructure — plans and signup are on ranla.ai.
FAQ
Questions from teams sending transactional email
What does SuperSend TX do?
Critical transactional email: order confirmations, receipts, alerts, auth mail, and other messages that have to arrive — plus inbound, webhooks, templates, automations, SMTP, SDKs for five languages, a CLI, and MCP on the same platform.
Who is it for?
Teams whose transactional email cannot risk noisy shared pools. Pool covers most senders. Dedicated is for teams that need their own servers and IPs.
What is Pool vs Dedicated?
Pool is our shared transactional network — no marketing or cold email on that pipe. Free production and paid volume both use it. Dedicated is not just a new IP: we provision your own mail server (or servers), assign IPs, warm them, and manage the stack. Same API either way.
How is Dedicated different from a "dedicated IP" add-on?
Many providers sell a single IP on shared infrastructure. Dedicated on SuperSend TX means your own mail server and IPs. We build it, warm it, and operate it. Your IP is listed in the dashboard for allowlists and security reviews. Exact capacity is scoped on a demo.
Which languages have an SDK?
Node/TypeScript (supersendtx on npm), Python (supersendtx on PyPI), PHP (supersendtx/supersendtx on Packagist), Ruby (supersendtx on RubyGems), and Go (github.com/Super-Send/supersendtx-sdks/go) — plus a Laravel package with config and a facade. All five wrap the same REST API, so anything not covered by an SDK is still one HTTP call away.
Do you have a CLI and MCP?
Yes. supersendtx-cli for the terminal and supersendtx-mcp (hosted OAuth MCP plus local stdio) with Agent Skills. MCP exposes a curated tool set — use an SDK or the CLI for full API breadth.
Can I receive inbound email?
Yes. Enable inbound on a domain (prefer a subdomain for MX), subscribe to email.received webhooks, and inspect mail in the Inbound dashboard.
Do you support SMTP?
Yes. smtp.supersendtx.com:587 with dashboard SMTP credentials. Same verified domains, billing limits, and suppressions as the HTTP API — useful for Supabase, Clerk-style providers, and legacy clients.
Do you have templates and automations?
Yes. A visual block editor with versioned publish, {{variables}}, and a starter gallery. Teammates edit in the dashboard; engineers send by alias (React Email, CLI push, or raw HTML). Automations trigger from POST /events into multi-step flows with conditions and run history.
How is this different from Resend?
Production runs on a transactional-only network we operate — not mixed with marketing or cold outbound. Free includes capped production after a verified domain and payment method on file. Dedicated is a managed server and IPs, not an IP label on someone else’s shared platform.
How is this different from Postmark or SendGrid?
Transactional stays separate from cold outbound. Dedicated is a real isolation tier with managed servers, not locked behind huge volume minimums.
How is this different from SuperSend Outbound?
Outbound is for cold email. SuperSend TX is for transactional email only. Cold sending never touches your critical mail.
What does pricing look like?
Free includes 3,000 emails/mo and 100/day after you verify a domain and add a payment method (no charge until you upgrade). Before that you can self-test to your account email with the sandbox sender. Pro starts at $20/mo for 50,000 emails. Scale tiers add volume with declining overage per 1,000 emails and up to 1,000 domains. Dedicated starts at $299/mo — your own servers and IPs, scoped on a demo.
How long until we can send?
Sandbox self-tests are immediate. For Free production sending: verify DNS, add a payment method, then send to real recipients within Free caps. Upgrade to Pro or Scale for higher volume — checkout takes minutes. Dedicated is set up with our team once we have a warmed server for you.
SuperSend TX is now Ranla
Same critical transactional email on the same infrastructure — signup and pricing live on ranla.ai, with an AI growth marketer included.