Email Sending API
Integrate lightning-fast email delivery into your apps with SMTPMaster’s secure REST API. Send transactional emails, OTPs, invoices, alerts, and marketing campaigns — built for scale.
Fast Integration
Enterprise Security
94.5% Inbox Rate
curl -X POST https://api.smtpmaster.com/api/send-email \
-H "X-API-Key: YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"from_email": "sender@example.com",
"from_name": "test",
"to_email": "receiver@example.com",
"subject": "Test email from Sending API",
"body": "Hello, this is a test email sent through the Sending API."
}'
Email Statistics features
Analyze delivery outcomes, sending volume, and campaign health so your team can optimize inbox placement and troubleshoot faster.
GET https://api.smtpmaster.com/api/user-email-Statistics?date=YYYY-MM-DD
X-API-Key: YOUR_API_KEY
Accept: application/json
{
"success": true,
"stats": {
"total_sent": 12450,
"total_delivered": 12000,
"total_bounce": 450,
"hard_bounce": 120,
"soft_bounce": 330
}
}
- Delivery statusReview accepted, delivered, bounced, deferred, and failed message totals.
- Sending volumeCompare API usage by day, campaign, sender, or application workflow.
- Engagement signalsTrack opens, clicks, spam complaints, and bounce patterns in one view.
- Export-ready reportsUse reporting data for audits, client updates, and deliverability reviews.
Email log features
Find the exact message you need, verify recipient-level activity, and follow each delivery event without leaving the log view.
GET https://api.smtpmaster.com/api/user-email-logs?category=ALL&date=YYYY-MM-DD&limit=50
X-API-Key: YOUR_API_KEY
Accept: application/json
{
"success": true,
"has_more": true,
"next_cursor": "NEXT_CURSOR_VALUE",
"data": [
{
"status": "Delivered",
"sender": "sender@example.com",
"recipient": "client@gmail.com",
"time": "2026-08-11 10:15:22",
"subject": "Welcome to SMTPMaster"
}
]
}
- Recipient recordsView recipient address, subject, sender, and request details for each email.
- Event timelineFollow sent, queued, delivered, bounced, opened, and clicked events.
- Advanced filtersSearch by status, recipient, date range, campaign, or message activity.
- Troubleshooting dataUse timestamps, errors, and bounce reasons to resolve delivery issues.
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 & reliable password recovery emails for any platform.
E‑commerce Notifications
Order confirmations, shipping updates, and digital receipts.
Billing & Invoices
Automated billing emails, subscription invoices & payment reminders.
CRM Integrations
Sync customer communication and engagement workflows.
SaaS Alerts
Real‑time app notifications, usage alerts, and product updates.
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 & 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 & 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 & username from SMTPMaster dashboard.
STEP 2
Integrate API
Use our ready 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.
Start Sending 9,000 Emails At No Cost
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
emails Credits every month
- 300 emails per day
- SMTP credentials included
- Email logs and tracking
- SPF, DKIM and DMARC setup
Trusted by Developers, SaaS & Growing Teams
Real customer feedback from SMTPMaster's Trustpilot reviews.
Works with Your Tech Stack
Native SDKs and libraries for all popular languages & frameworks.
Python
Java
Node.js
PHP
Ruby
Download Email API Documentation
Access complete developer documentation including:
- Authentication
- Request Parameters
- Response Examples
- Dynamic Variables
- Error Handling
- Best Practices
Note: Use a Verified Sending Domain
To ensure reliable email delivery, you must send emails only from domains that have been verified and authenticated in your SMTPMaster account.
Emails sent using an unverified or unauthorized sender domain may be rejected, fail to send, or result in delivery errors and bounces.
For consistent delivery and to avoid sending-related issues, always use your own verified domain as the sender domain when using the SMTPMaster Email API.
Start Sending Transactional & Bulk Emails in Minutes
Integrate a powerful email API built for developers, startups, and global enterprises. Get high deliverability, real-time analytics, and dedicated support.
