Email communication is the backbone of every online business. Whether you’re sending transactional messages, newsletters, or account alerts, a reliable SMTP Relay Providers ensures your emails reach inboxes — not spam folders.
What is an SMTP Relay Service?
SMTP (Simple Mail Transfer Protocol) relay is a process that lets you send emails through a third-party server. Instead of managing your own email infrastructure, an SMTP provider handles it for you—improving deliverability, speed, and scalability.
Why Use an SMTP Relay Provider?
- Improved inbox delivery
- Avoid blacklisting and IP bans
- Analytics & bounce tracking
- Easy integration with websites, apps, and CRMs
Top 15 SMTP Relay Providers (Free & Paid Plans)
| SMTP Provider | Free Plan Available | Key Features |
|---|---|---|
| Sendinblue | ✅ Up to 300 emails/day | Email marketing, transactional, API, great UI |
| Mailgun | ✅ 5,000 emails/month for 1st 30 days | Developer-friendly, robust analytics |
| Amazon SES | ✅ With AWS Free Tier | Affordable, scalable, requires setup |
| SMTP2GO | ✅ 1,000 emails/month | High deliverability, easy setup |
| Postmark | ❌ No free plan | Fast delivery, best for transactional emails |
| Mailchimp (Transactional) | ❌ Paid only | Well-known, good analytics |
| Brevo (formerly Sendinblue) | ✅ Same as above | Email + SMS, intuitive dashboard |
| Elastic Email | ✅ 100 emails/day | Pay-as-you-go option, marketing & SMTP |
| Moonsend | ❌ Paid only | Clean UI, marketing-focused |
| SocketLabs | ✅ 2,000 emails/month | Powerful SMTP with API and analytics |
| SendPulse | ✅ 12,000 emails/month | Email + push + SMS |
| Pepipost (Netcore) | ❌ Merged with Netcore Cloud | Transactional focus, fast delivery |
| Google Workspace SMTP | ❌ No real free plan | Trusted brand, 2,000 messages/day limit |
| TurboSMTP | ✅ 6,000 emails/month | Simple, affordable SMTP option |
| Mailjet | ✅ 6,000 emails/month | Real-time collaboration, decent API |
1. Sendinblue (Brevo)
- Best for: Small to mid-size businesses
- Free Plan: 300 emails/day
- Features: SMTP relay, marketing automation, SMS, API access
2. Mailgun
- Best for: Developers and transactional emails
- Free Trial: 5,000 emails for 30 days
- Features: Excellent API, domain authentication, analytics
3. Amazon SES
- Best for: High-volume senders
- Pricing: Extremely low-cost
- Cons: Requires technical setup
4. Postmark
- Best for: Speed-sensitive transactional emails
- Free Plan: None
- Pros: Amazing deliverability, developer-focused
5. SMTP2GO
- Free Plan: 1,000 emails/month
- Pros: Easy to set up, reports, great uptime
Choosing the Right SMTP Relay Provider
Here’s what to consider:
- Budget: Need free or low-cost options?
- Integration: Does it work with your platform?
- Volume: Are you sending 100 or 100,000+ emails a month?
- Security: Does it offer TLS, SPF/DKIM setup?
Best Free SMTP Providers (Summary)
If you’re on a budget or just starting:
- Sendinblue – Great free tier, easy UI
- Mailjet – Flexible pricing and analytics
- SendPulse – Up to 12,000 free emails/month
- Elastic Email – Pay-per-use pricing, good API
Best Paid SMTP Providers for High Volume
For businesses that need guaranteed deliverability:
- Postmark
- Amazon SES
- Mailgun
- SMTP2GO
FAQs
Q1. What is the best free SMTP relay provider?
Sendinblue and SendPulse offer generous free plans and are easy to set up.
Q2. Is Amazon SES good for beginners?
Not really. It’s powerful and cheap but requires some technical knowledge to configure properly.
Q3. Can I use SMTP relay with WordPress?
Yes! Most SMTP providers offer plugins or documentation to connect with WordPress easily.
Q4. Is SMTP secure?
Yes, as long as you enable TLS/SSL encryption and authenticate your domain (SPF, DKIM).
Final Thoughts
Finding the right SMTP service provider depends on your needs—volume, budget, and features. Whether you’re sending transactional emails from your app or running a newsletter for your audience, the options above cover both free and premium solutions you can trust in 2025.