High-Performance SMTP Relay for Developers
Send transactional and bulk email through our globally distributed SMTP infrastructure. Sub-second delivery, automatic failover, and detailed delivery logs — built for applications that can't afford downtime.
Key Features
Everything you need to smtp relay effectively, built into one platform.
Global Edge Network
Send from 12 data centers worldwide. Emails route through the nearest node for minimum latency and maximum delivery speed.
Dedicated IP Addresses
Get your own IP with full reputation control. Includes automated IP warming and blacklist monitoring.
Automatic Failover
Multi-path routing with instant failover ensures your emails are delivered even during regional outages.
Real-Time Logs
Track every message with detailed SMTP logs — accepted, delivered, bounced, deferred, and rejected events.
TLS Encryption
All connections secured with TLS 1.3. Support for STARTTLS, SSL/TLS ports 465 and 587.
Volume Scaling
From 100 emails/day to 10 million+/day without infrastructure changes. Pay only for what you send.
Learn More
Dive deeper into how SprintMailer helps you achieve better results.
SMTP Infrastructure You Can Trust
When your application sends password resets, order confirmations, or marketing blasts, downtime isn't an option. SprintMailer's SMTP relay is engineered for reliability at scale.
Our infrastructure processes over 2.5 billion emails monthly with a 99.99% uptime SLA. Automatic retries, intelligent queue management, and ISP-specific throttling ensure maximum deliverability.
Simple Integration, Powerful Results
Connect in minutes using standard SMTP credentials or our REST API. SprintMailer works with any application, framework, or programming language.
We provide SDKs for Node.js, Python, PHP, Ruby, Go, and .NET, plus comprehensive API documentation with copy-paste examples.
Dedicated IPs & Domain Authentication
Shared IP pools work for low volumes, but high-volume senders need dedicated IPs to protect their sender reputation. SprintMailer offers:
Dedicated IP provisioning
with automated 30-day warming schedule
Custom reverse DNS (rDNS)
matching your sending domain
SPF, DKIM, DMARC
setup wizard with DNS record validation
Feedback loop processing
for Gmail, Yahoo, Microsoft, and AOL
Monitoring & Deliverability Insights
Every SMTP transaction is logged and searchable. Filter by recipient, status, time range, or error code. Set up webhooks to receive real-time delivery events in your application.
Our deliverability dashboard shows bounce rates, complaint rates, and inbox placement trends over time — so you can catch problems before they affect your sender reputation.
Frequently Asked Questions
Common questions about smtp relay.
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Get your SMTP credentials in under 5 minutes. Free tier includes 1,000 emails/month.
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