Free Transactional Email API for Developers
Start with 9,000 free emails per month and connect SMTPMaster to your app for OTPs, password resets, invoices, alerts, and onboarding emails.
Quick setup. Built for developers and growing teams.
9,000 Free Emails/Month
API + SMTP Relay
94.5% Inbox Rate
Launch email delivery without upfront cost
300
emails per day
9,000
emails per month
Email
API integration
OTP
alerts and invoices
- Send from your app using secure API credentials.
- Handle transactional workflows like signup, login, billing, and notifications.
- Scale from free testing to production sending when your traffic grows.
Start Sending 9,000 Emails for Free
Connect your app to SMTPMaster's Email Sending API and test real transactional emails without upfront cost. Send OTPs, password resets, invoices, alerts, and onboarding emails while you build, launch, and scale.
$0
Forever
9,000
email credits every month
- 300 emails per day
- SMTP credentials included
- Delivery activity tracking
- SPF, DKIM and DMARC setup
What Can You Build With SMTPMaster Email API?
From authentication flows to transactional workflows, the API adapts to every need.
OTP Verification
Deliver one-time passwords instantly with high priority routing.
Account Registration
Welcome emails, activation links, and user onboarding automation.
Password Reset
Secure and reliable password recovery emails for any platform.
E‑commerce Notifications
Order confirmations, shipping updates, and digital receipts.
Billing and Invoices
Automated billing emails, subscription invoices, and payment reminders.
CRM Integrations
Sync customer communication and engagement workflows.
Marketing Campaigns
Targeted newsletters, promo campaigns and re-engagement flows.
Bulk Emails
Reach thousands of customers with reliable bulk email delivery.
Powerful Email Sending Features
Everything you need to build world-class email experiences.
HTML + Rich Templates
Design beautiful emails with full HTML/CSS support and inline styling.
Plain Text Fallback
Auto plain-text version for maximum compatibility and spam score.
Dynamic Variables
Personalize emails with custom placeholders and merge tags.
Bulk and Batch Sending
Send to thousands of recipients with CC/BCC and smart throttling.
Real-time Analytics
Open, click, bounce, and spam complaint tracking via dashboard.
Webhooks and Events
Receive delivery events and engagement data in real time.
How SMTPMaster Email API Works
Four simple steps to integrate and send emails in minutes.
STEP 1
Generate Credentials
Create API key and username from SMTPMaster dashboard.
STEP 2
Integrate API
Use SDKs or direct REST endpoints.
STEP 3
Send Request
POST JSON payload with email data + recipients.
STEP 4
Email Delivered
Emails land in inboxes with dedicated infrastructure.
Works with Your Tech Stack
Native SDKs and libraries for popular languages and frameworks.
Python
Java
Node.js
PHP
Ruby
SMTPMaster on Trustpilot
Explore verified customer feedback, service experiences, and public reviews directly on Trustpilot before choosing SMTPMaster for transactional email delivery.
Start Sending Transactional and Bulk Emails in Minutes
Integrate a powerful email API built for developers, startups, and growing teams. Get high deliverability, real-time analytics, and dedicated support.
