Transactional Email Infrastructure Setup Under 5 Clicks

Send OTPs, password resets, receipts, and system alerts with guaranteed inbox placement. No SMTP configuration, no DNS headaches, no app passwords.

Get Started Free View Docs

7 day free trial. No credit card required.

< 5s Average Time to Inbox

Delivered fast via optimized infrastructure and multi-region routing.

99.77% Deliverability Rate

SPF, DKIM, DMARC-ready with trusted providers for maximum inbox placement.

100% Delivery Transparency

Track delivery, opens, clicks, and full email timelines in one place.

Trusted by world-class developers & industry leading teams

Swing Technologies - using Keplars transactional email API

FoundersBoxx - startup platform using Keplars email infrastructure

GitStart - developer platform powered by Keplars email API

Microsoft - enterprise team using Keplars transactional email service

Roostoo - fintech app sending emails via Keplars

Supabase - open source backend using Keplars email delivery

Touchstack - product team using Keplars for transactional emails

Oryan - using Keplars email infrastructure

Everything You Need to Send with Confidence

Built for developers who need reliable, fast, and measurable email delivery without the infrastructure overhead.

Instant Delivery

OTPs, password resets, and alerts reach inboxes in milliseconds, not seconds. No queues, no delays.

99.77% Inbox Rate

Backed by Gmail, Google Workspace, and Outlook infrastructure with SPF, DKIM, and DMARC verified by default.

Under 5-Minute Setup

Generate API keys or SMTP credentials from your dashboard and send your first email in minutes. No DNS fiddling.

Developer-First API

REST API, SMTP relay, and Webhooks. Send from any language or framework.

Custom Domain Support

Bring your own domain and send as [email protected] with full SPF + DKIM + DMARC verification.

Delivery Analytics

Track opens, clicks, bounces, and delivery status in real time. Detailed logs for every transactional event.

REST APIasync

send-email.js

1const axios = require('axios');
2
3const client = axios.create({
4  baseURL: 'https://api.keplars.com',
5  headers: {
6    'Authorization': 'Bearer kms_3725865b5eee62f0.*******************************'
7  }
8});
9
10await client.post('/api/v1/send-email/instant', {
11  to: ['[email protected]'],
12  subject: 'Your 2FA Code',
13  body: '<b>Your verification code is: 123456</b>',
14  is_html: true
15});

SMTP Relayport 587

smtp-config.txt

1Host:     smtp.keplars.com
2Port:     587  (recommended, STARTTLS)
3Security: STARTTLS
4Username: [Your generated username]
5Password: [Your generated password]

Integrate in minutes, not days.

Full API reference, webhook docs, and code examples. Everything you need to go live fast.

Read Documentation

Webhooks

Real-time event notifications for every email lifecycle state.

email.sentemail.queuedemail.deliveredemail.bouncedemail.failedemail.rejectedemail.openedemail.clickedemail.spamemail.complaintemail.warning

Start sending transactional emails in under 5 clicks

5,000 emails/month for $1. No credit card needed.

Customise your Pricing Explore Marketing Emails