Self-hosted email infrastructure

Email delivery you can actually inspect.

A transactional email API and SMTP relay running on our own mail servers. Verify your domain, send with one request, and follow every message from submission to the recipient server's reply.

  • Own mail servers, no resold provider
  • DKIM 2048-bit signing
  • Real SMTP responses

Platform

Everything a transactional email pipeline needs

From the first API call to the last bounce, every step is visible and under your control.

REST API

One JSON request to send. Idempotency keys, templates, attachments, tags and metadata built in.

Authenticated SMTP

Drop-in SMTP on port 587 with STARTTLS and per-application credentials restricted to your domains.

Domain authentication

Guided SPF, DKIM (2048-bit) and DMARC setup with live DNS checks and safe key rotation.

Message timeline

Every submission, hand-off, deferral, acceptance and bounce — with the real SMTP response from the receiving server.

Signed webhooks

HMAC-signed events with timestamps, retries with backoff, test events and full delivery history.

Bounces & suppressions

Hard bounces and complaints are suppressed automatically so you protect your sender reputation.

REST API

Send with a single request

Authenticate with a scoped API key, post JSON, and get back a message ID immediately. Delivery happens asynchronously; follow it through the events API or signed webhooks.

  • Idempotency keys prevent accidental duplicates
  • Templates with escaped variables
  • Attachments, tags and metadata
  • Clear error codes and rate-limit headers
curl https://api.sendoryn.com/v1/emails \
  -H "Authorization: Bearer gw_live_xxxxxxxxxxxx_your_secret" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: welcome-user-123" \
  -d '{
    "from": "Acme <[email protected]>",
    "to": ["[email protected]"],
    "subject": "Welcome",
    "html": "<h1>Welcome!</h1>",
    "text": "Welcome!",
    "tags": ["welcome"],
    "metadata": { "source": "website" }
  }'
SMTP_HOST=mail.sendoryn.com
SMTP_PORT=587
SMTP_SECURE=false        # STARTTLS is negotiated on port 587
SMTP_USER=smtp_xxxxxxxxxxxxxxxx
SMTP_PASSWORD=your_smtp_password

SMTP

Already speak SMTP? Change two settings.

Authenticated submission on port 587 with STARTTLS. Credentials are scoped to your organization and can be restricted to specific verified domains — messages from any other sender are refused.

Domains

Authenticated from the first message

A guided wizard generates every DNS record, checks them live, and only enables sending once your domain is proven and signed.

  1. 1

    Add domain

    Enter the domain you send from.

  2. 2

    Prove ownership

    Publish a unique TXT token.

  3. 3

    SPF & DKIM

    Authorize our servers and publish your 2048-bit public key.

  4. 4

    Verify

    We resolve the records server-side and show exactly what's wrong.

  5. 5

    Send

    Sending unlocks only after required checks pass.

Infrastructure

Honest delivery, run on our own servers

We operate the mail transfer agents that talk to recipient servers. No hidden third-party relay, and no vanity metrics.

Direct delivery

Postfix-based MTAs deliver straight to recipient mail exchangers with TLS where offered, managed retry schedules, and per-tenant throttling.

Reputation protection

Account review, automatic suppression of hard bounces and complaints, and abuse monitoring keep shared infrastructure clean.

Secure by default

Hashed API keys, encrypted signing keys, TOTP 2FA, audit logs and strict tenant isolation on every query.

Pricing

Simple plans that scale with you

Every plan includes the API, SMTP, domain authentication and delivery events.

Pay as you go

No monthly fee. Pay only for what you send.

$0.10

per 1,000 emails · no monthly fee

Get started

Starter

For products sending real volume.

$5/month

100,000 emails / month

Get started
Most popular

Growth

For growing teams with steady volume.

$20/month

500,000 emails / month

Get started

Business

High volume at the lowest price per email.

$60/month

2,000,000 emails / month

Get started

Enterprise

Custom volume, limits and terms.

Custom

Custom volume

Contact sales

Compare all plan limits →

Developer experience

Docs, OpenAPI spec and examples in four languages.

Every endpoint is described in an OpenAPI 3.1 document, with copyable examples for cURL, Node.js, Python and PHP, signed webhook verification code and a full error reference.

FAQ

Questions, answered plainly

Do you guarantee inbox placement?+

No one can. Receiving providers decide where mail lands. We handle the parts we control — authentication (SPF, DKIM, DMARC alignment), clean infrastructure, correct bounce handling and suppression — and show you exactly how each recipient server responded.

What does “accepted” mean in the dashboard?+

It means the recipient's mail server replied 250 to our delivery attempt and took responsibility for the message. It is not proof the message reached the inbox, and we never label it that way.

Do you send through a third-party provider?+

No. Messages are delivered directly from our own mail servers to recipient mail exchangers. We do not resell another email provider.

Can I use SMTP instead of the API?+

Yes. Create SMTP credentials in the dashboard and point any SMTP-capable application at our submission server on port 587 (STARTTLS).

Is marketing email allowed?+

Only after account review, and only to people who opted in. Each contact needs a consent record, every message carries one-click unsubscribe, and purchased or scraped lists are not permitted.

Why does my account need approval?+

Every new account is reviewed before it can send. It keeps abusive senders off shared infrastructure, which protects deliverability for every customer.

Sendoryn — Transactional email on infrastructure you can see.