11 Best SMTP Relay Service 2025: Up to 15k emails/month

 Have you ever spent hours crafting the perfect email campaign, only to see it land in the spam folder? Or worse, not get delivered at all? Email marketing is one of the most powerful tools for businesses, but without a reliable SMTP Relay Service, your efforts might be going to waste.

Many businesses make the mistake of using poor-quality SMTP servers, which result in low deliverability, email bounces, and even blacklisting. But don’t worry—we’ve researched for you! In this guide, we’ll introduce the 11 best SMTP relay services for 2025 that allow you to send up to 15,000 emails per month without hassle.

What is an SMTP Relay Service?

SMTP (Simple Mail Transfer Protocol) relay services help businesses send emails in bulk while ensuring high inbox placement, lower bounce rates, and better security. These services act as a bridge between your email-sending software and the recipient's inbox, preventing issues like ISP restrictions and spam filters.

Now, let’s dive into the top 11 SMTP Relay Services for 2025 that offer up to 15k emails per month.

1. iDealSMTP – Best for High Inbox Placement

Free Emails/Month: Up to 15,000
Pricing: Starts at $10/month
Key Features:

• High deliverability rates

• Dedicated IPs for better control

• Advanced security features

iDealSMTP is an excellent choice for businesses looking for high inbox placement and dedicated IPs. Their service ensures that your emails are delivered fast and reliably.

2. SMTP.com – Reliable & Scalable

Free Emails/Month: 12,000
Pricing: From $25/month
Key Features:

• Robust API integration

• Email analytics

• 24/7 customer support

SMTP.com is a trusted name in the industry, known for its high email delivery rates and scalable solutions. It’s great for both small businesses and large enterprises.

3. Sendinblue – Best for Marketing Automation

Free Emails/Month: 15,000
Pricing: Starts at $0 (free plan available)
Key Features:

• Built-in email automation

• Transactional email support

• Drag-and-drop email editor

Sendinblue is perfect for businesses looking for marketing automation and transactional emails. The free plan allows up to 15,000 monthly emails, making it a great choice for startups.

4. Mailgun – Best for Developers

Free Emails/Month: 10,000
Pricing: Starts at $35/month
Key Features:

• Powerful API for email integration

• High deliverability with real-time analytics

• Advanced spam filtering

Mailgun is developer-friendly and provides advanced email-sending capabilities, making it ideal for SaaS companies and tech businesses.

5. SendGrid – Best for Scalability

Free Emails/Month: 15,000
Pricing: Starts at $14.95/month
Key Features:

• Cloud-based SMTP solution

• Customizable email templates

• Strong email authentication

SendGrid is backed by Twilio, making it one of the most scalable solutions for high-volume email senders.

6. SMTP2GO – Best for Email Analytics

Free Emails/Month: 10,000
Pricing: Starts at $10/month
Key Features:

• Real-time email tracking

• Instant email reports

• 24/7 support

SMTP2GO ensures that you get detailed analytics and tracking to improve email performance.

7. Postmark – Best for Transactional Emails

Free Emails/Month: 15,000
Pricing: Starts at $15/month
Key Features:

• Lightning-fast email delivery

• High inbox placement

• Developer-friendly API

Postmark is a great choice if you need reliable transactional email delivery.

8. Amazon SES – Best for Cost-Effective Bulk Emails

Free Emails/Month: 15,000 (AWS-hosted apps only)
Pricing: Pay-as-you-go
Key Features:

• Highly affordable

• Scalable for large businesses

• Strong security features

Amazon SES is one of the most cost-effective SMTP solutions, especially for businesses already using AWS.

9. Moosend – Best for Small Businesses

Free Emails/Month: 15,000
Pricing: Starts at $9/month
Key Features:

• User-friendly interface

• Email marketing automation

• Customizable templates

Moosend is ideal for small businesses looking for a simple and affordable SMTP solution.

10. Pepipost – Best for AI-Powered Email Delivery

Free Emails/Month: 15,000
Pricing: Starts at $17.50/month
Key Features:

• AI-driven email optimization

• High email open rates

• Secure email infrastructure

Pepipost uses AI to enhance email delivery and increase engagement.

11. Mailjet – Best for Collaboration

Free Emails/Month: 15,000
Pricing: Starts at $15/month
Key Features:

• Team collaboration tools

• Advanced email editor

• API integrations

Mailjet is perfect for teams who need to work together on email campaigns.

How to Choose the Right SMTP Relay Service?

With so many great options, here’s how to choose the best SMTP Relay Service for your needs:

✅ For Bulk Emails: iDealSMTP, SMTP.com, Amazon SES
✅ For Marketing Automation: Sendinblue, Moosend
✅ For Developers: Mailgun, Postmark
✅ For Transactional Emails: SendGrid, SMTP2GO
✅ For Small Businesses: Mailjet, Pepipost

Final Thoughts

Choosing the right SMTP relay service can make or break your email marketing efforts. If you want high deliverability, security, and affordability, these 11 SMTP providers are your best bet for 2025.