Transactional Email API

Transactional email for mission critical messages.

Send password resets, OTPs, receipts, account alerts, and product notifications through Leadpush's SDK, REST API, or SMTP relay.

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POST /emails

Send transactional email with REST

curl -X POST https://api.leadpush.io/v1/workspaces/:workspace/emails \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer {token}" \
  -d '{
    "from": "alerts@example.com",
    "to": ["customer@example.com"],
    "subject": "Your verification code",
    "html": "<p>Your code is 482910</p>"
  }'

Transactional Email API Use Cases

Send event-triggered product email from your application.

Use the Leadpush transactional email API for messages your users expect after a product action, account event, or system update. Each send can carry the payload, sender, subject, HTML, text, reply-to, and header context your application controls.

Critical path API traffic

Keep authentication, billing, security, and product-triggered messages on one observable delivery layer so engineers can trace API requests, delivery events, and webhook callbacks when a customer-facing flow needs attention.

API-triggered email

Authentication

Trigger password resets, magic links, one-time codes, and verification emails from login and account recovery flows.

Password resets, magic links, OTPs, verification emails

Password Reset Emails OTP Emails

API-triggered email

Billing + Commerce

Send receipts, invoices, payment confirmations, and account notices from checkout, billing, and renewal events.

Receipts, invoices, payment confirmations, billing notices

Receipt Emails

API-triggered email

Security Alerts

Notify customers about suspicious activity, password changes, policy updates, and sensitive account events.

Suspicious login alerts, password changes, policy notices

Account Alert Emails

API-triggered email

Product Notifications

Trigger app-generated updates, onboarding nudges, usage milestones, and service messages from backend events.

Usage updates, onboarding nudges, status messages

API Delivery Visibility

Trace each transactional email from API request to delivery feedback.

A send endpoint is only the start. Leadpush gives engineers queue state, routing context, suppression checks, delivery events, webhook callbacks, and sender visibility for high-priority product email.

Queue + retry visibility

Handle bursty API sends with clear queue state, retry behavior, and less guesswork around in-flight transactional email.

Routing decisions in view

See routing context as workload, provider behavior, or sender reputation changes affect delivery decisions.

Suppression + sender health

Protect important product messages with suppression awareness, sender signal visibility, and clearer investigation paths.

Transactional Send Console

See what happened after every API send.

Critical path delivery

Queue

Password reset and OTP API traffic draining normally

Routing

Primary path selected for authentication and alert sends

Events

Delivered, deferred, bounced, and complaint signals ready for webhook callbacks

Delivery event trace

QueuedAcceptedDeliveredDeferredBouncedComplainedWebhook callbacksSearchable logsSuppression hits

Follow a transactional email from request payload to provider response to webhook callback so engineers can debug customer-facing issues with real delivery context.

Integration Paths

Choose the transactional email API path that fits your stack.

Start with REST API sends for direct application control, use SMTP relay for existing mailers, and connect delivery feedback to the systems your team already uses.

REST API

Post transactional sends from backend services, workers, and internal platforms with authenticated JSON payloads.

Best for password resets, OTPs, receipts, alerts, and direct service-to-service delivery.

View send endpoint

SMTP Relay

Point existing application mailers at Leadpush so you can migrate transactional delivery without refactoring every send path first.

Best for legacy apps, framework mailers, vendor migrations, and low-code transport changes.

Read SMTP setup

Delivery Events + Webhooks

Use message events and webhook callbacks to connect delivery feedback back to your product, support, or operations workflow.

Best for debugging delayed sends, bounce handling, suppression checks, and customer-facing delivery investigations.

Explore webhooks

FAQ

Transactional email API questions.

Practical answers for teams comparing API-first transactional email, SMTP relay, and delivery feedback workflows.

What is a transactional email API?

A transactional email API lets an application send event-triggered email such as password resets, OTPs, receipts, account alerts, and product notifications through authenticated API requests.

Can Leadpush send transactional email through both API and SMTP?

Yes. Leadpush supports REST API sending for direct application integration and SMTP relay for existing mailers, legacy systems, and migrations.

How do teams debug transactional email delivery issues in Leadpush?

Teams can use delivery events, webhook callbacks, queue state, retry context, searchable logs, suppression signals, routing context, and sender visibility to trace what happened to important sends.

Which product emails should use a transactional email API?

Transactional email APIs are built for messages triggered by user or system events, including password resets, magic links, OTPs, verification emails, receipts, invoices, account alerts, and product notifications.

Evaluate Leadpush

Start with the transactional email API docs.

Review the send endpoint, authorization flow, and pricing options for password resets, OTPs, receipts, alerts, and other product-triggered email.

View API Docs View Pricing