Senda
Senda
Senda
Email API & SMTP

Enterprise-grade email API & SMTP infrastructure

Senda's multi-server sending infrastructure with automatic IP warmup, load balancing, and real-time deliverability tracking gives you the reliability and scale your application needs.

See API pricing

What you can do

Senda gives you everything you need to send, route, and track emails at scale.

Send via SMTP or REST API
Route through Amazon SES, SendGrid, or Mailgun
Warm up new IP addresses
Verify email lists before sending
Track delivery in real-time
Set up webhooks for event notifications

API plans from $19/month

See all plans

Everything you need for email delivery

A complete toolkit for sending, routing, and tracking your email infrastructure.

Integration
  • REST API
  • Amazon SES
  • SendGrid
  • Mailgun
  • SparkPost
  • ElasticEmail
  • Generic SMTP
  • Local mailers
Infrastructure
  • Multi-server load balancing
  • IP Warmup (Linear & Exponential)
  • Per-server quotas
  • Distributed workers
  • Supervisor concurrency
  • Redis queues
Tracking
  • Open/click tracking
  • Bounce classification
  • Complaint/FBL handling
  • GeoIP tracking
  • Device/OS tracking
  • Real-time dashboard

Sending Drivers

Route email through any provider

Senda supports a wide range of sending drivers — from cloud APIs like Amazon SES and SendGrid to local MTAs like Postfix and Exim. Mix and match to build the sending infrastructure that works for you.

Amazon SES
SendGrid (API+SMTP)
Mailgun
SparkPost
ElasticEmail
Postal
Gmail OAuth
Postfix/Exim/Sendmail
Generic SMTP
send-email.js
const senda = require('senda-sdk')(API_KEY);
 
await senda.emails.send({
to: 'user@example.com',
from: 'hello@yourdomain.com',
subject: 'Welcome!',
template: 'welcome-v2',
});
 
// Response: { id: msg_abc123, status: sent }
IP Warmup Progress
Day 14 of 30 — Linear Ramp
On Track
Day 1Day 7Day 14
5,000
Today's Quota
14
Days Elapsed
50K
Target/Day

IP Warmup

Warm up new IPs safely and automatically

Building sender reputation on a new IP doesn't have to be manual. Senda's built-in IP warmup engine gradually increases your daily sending volume, following proven strategies that ISPs trust.

Linear ramp

Gradually increase daily sending volume in equal increments. Ideal for new IPs that need steady, predictable growth to build sender reputation.

Exponential ramp

Accelerate sending volume progressively, doubling at safe intervals. Best for established senders who want to scale faster while maintaining deliverability.

Auto daily quota management
Per-server warmup state tracking
No external service needed

Security

Enterprise-grade security for your email infrastructure

Your data is protected at every layer. Senda maintains the highest security standards so you can focus on building your product without worrying about email vulnerabilities.

Start sending securely
SPF
DKIM
DMARC
2FA
API Keys
TLS Encryption
IP Allowlisting
Rate Limiting

Email Verification

Verify email lists before you send

Reduce bounces and protect your sender reputation by verifying email addresses before they enter your lists. Senda integrates with leading verification services so you can clean your data with a single click.

Supported integrations

Emailable
Kickbox
ZeroBounce
Debounce

Verification results

DeliverableUndeliverableRisky
Email Verification
Verify List
8,432
Deliverable
341
Undeliverable
127
Risky
Verification Progress95%
sarah@company.comDeliverable
john@invalid.orgUndeliverable
alex@temp-mail.ioRisky

Frequently asked questions

Find answers to common questions about Senda's Email API, SMTP, and sending infrastructure.

Ready to scale your email infrastructure?

Instant setup. No credit card required.