Email infrastructure
developers trust
SPF / DKIM / DMARC on autopilot. Every log, every bounce, every click. Drop-in SendGrid alternative with AI-powered deliverability.
Free up to 1,000 emails/month. No credit card required.
99.9%
Uptime SLA
<200ms
API latency
2M+
Emails sent
Everything you need to deliver
Production-ready email infrastructure with built-in best practices.
High Deliverability
Dedicated IPs, warm-up assistance, and AI optimization for inbox placement across all major providers.
Domain Auth on Autopilot
SPF, DKIM, and DMARC auto-configured. DNS verification with copy-to-clipboard records.
Real-time Analytics
Track opens, clicks, bounces, and delivery delays with per-email granularity.
Webhook Events
Instant event delivery for every send, bounce, open, click, and complaint.
Drop-in API
RESTful SMTP relay compatible with SendGrid, Mailgun, and Resend clients. Ship in minutes.
Suppression List
Auto-managed suppression for bounces and complaints. Protect your sender reputation.
Send emails in 3 lines
A simple API that just works. Swap from SendGrid in minutes.
await fetch('https://api.mailstack.io/v1/email/send', {
method: 'POST',
headers: {
'Authorization': 'Bearer ms_your_api_key',
'Content-Type': 'application/json',
},
body: JSON.stringify({
to: 'customer@example.com',
from: 'hello@yourdomain.com',
subject: 'Welcome aboard!',
html: '<h1>Welcome to our platform</h1>',
}),
});Trusted by developers worldwide
“Switched from SendGrid and cut our email costs by 80%. The API is beautifully simple.”
Sarah Chen
CTO at Nordflow
“The auto DKIM/SPF setup saved us hours. Deliverability is rock-solid across all providers.”
Marcus Eriksson
Lead Engineer at Stackwise
“Finally an email API that just works. The webhook events and analytics are exactly what we needed.”
Aisha Patel
Founder at LaunchPad
2M+
Emails delivered
500+
Developers
99.9%
Uptime SLA
<200ms
API latency
Start sending with confidence
Free up to 1,000 emails/month. DKIM, SPF & DMARC auto-configured. No credit card required.