Transactional email infrastructure

Email infrastructure for developers.

Send application-generated email through a developer-first API with verified domains, delivery events, suppression, and sender-protection controls.

Designed for password resets, OTPs, account verification, receipts, invoices, security alerts, and other expected application messages.

Node.jsPythonRESTSMTP
import { Sendout } from 'sendout';

const sendout = new Sendout('so_xxxxxxxxx');

await sendout.emails.send({
  from: 'onboarding@yourdomain.com',
  to: 'user@example.com',
  subject: 'Verify your email',
  html: '<strong>Welcome to Sendout</strong>'
});
Built for legitimate, expected application email — not unsolicited outreach.
Verified domainsDKIM/SPFSuppressionAbuse controlsWebhooks
Platform

Reliable sending starts with control.

Sendout is designed around authenticated senders, attributable customer activity, bounce and complaint handling, and clear acceptable-use rules.

Verified sender domains

Custom sending domains require DNS verification before production use.

Bounce & complaint suppression

Hard bounces and complaint recipients are blocked from repeated sending.

Delivery webhooks

Delivery lifecycle events can be delivered to customer endpoints in real time.

API + SMTP

Applications can integrate through REST, SDKs, or standard SMTP credentials.

Message observability

Delivery events and message metadata provide troubleshooting visibility.

Tenant-aware controls

Customer activity is attributable and subject to limits, review, and enforcement.

Sender protection

Built to protect recipients and reputation.

Every customer is responsible for permission, lawful sending, sender identity, and recipient expectations. Sendout prohibits purchased lists, scraping, spam, phishing, and cold outreach.

No unsolicited outreach

Cold email, scraped addresses, and purchased or rented recipient lists are prohibited.

Verified sender identity

Custom domains must be under the sender’s control and verified before production use.

Authenticated sending

Production sender configuration is expected to use DKIM and SPF; DMARC is strongly recommended.

Suppression

Hard-bounce and complaint recipients are blocked from repeated delivery attempts.

Customer enforcement

Suspicious accounts may be rate-limited, reviewed, paused, or terminated.

Recipient expectations

Senders must only deliver messages recipients reasonably expect to receive.

Sender safeguardsPolicy-backed controls
Custom domain ownershipRequired
Hard-bounce suppressionEnabled
Complaint suppressionEnabled
Purchased / scraped listsProhibited
Cold email / unsolicited outreachProhibited
Abusive customer activityReview / pause
Delivery events

See the email lifecycle.

Use event notifications to understand delivery outcomes, react to bounces and complaints, and keep application workflows in sync.

Webhook reference →
Event streamexample
10:24:12delivered→ user@example.com
10:23:54bounced→ invalid@domain.com
10:22:48complained→ recipient@example.com
10:21:03delivered→ customer@example.com
Policies

Clear rules for responsible sending.

The platform’s legal and operational policies define recipient acquisition, sender authentication, abuse response, suppression, privacy, and customer responsibilities.

Acceptable Use

What customers may send, what is prohibited, and when Sendout may intervene.

Read policy →

Anti-Spam

Rules for permission, expected messages, list acquisition, unsubscribe, and complaint handling.

Read policy →

Sender Requirements

Domain verification, authentication, recipient quality, and reputation responsibilities.

Read requirements →