6 Best Free SMTP Servers 2024

Free SMTP servers are a valuable resource for individuals and small businesses looking to send emails without incurring additional costs. These servers allow users to send transactional and marketing emails through a reliable and secure platform. The best free services are actually the Free editions of paid systems.

Here is our list of the best free SMTP servers:

1. EmailSuccess EDITOR’S CHOICE An on-premises system, this package is designed for high-volume email delivery with advanced features for optimizing deliverability and performance. Ideal for enterprise-level applications. The free plan allows 100,000 emails per day. Runs on Windows, Linux, VMware, Hyper-V, or Docker.
2. SendGrid Delivered from the cloud, this system provides a free plan with 100 emails per day. It’s known for its scalability, real-time analytics, and strong deliverability. Processes both transactional and marketing emails.
3. Elastic Email This cloud-based package offers a free plan with 100 emails per day. It’s user-friendly and integrates easily with various platforms, ensuring high deliverability.
4. Mailgun A cloud-based tool that offers a free plan with 100 emails per day. This developer-friendly platform has powerful APIs and high deliverability.
5. Inboxroad A cloud-hosted service with a free plan with 1,000 emails per month. It provides excellent deliverability rates and 24/7 support, making it a reliable choice.
6. Postmark This cloud-based package offers reliable and fast email delivery with the first 100 emails per month for free. Ideal for testing transactional emails or low-volume small businesses.

A transactional SNMP server passes through emails generated by another application, these are usually accessed through APIs. A transactional email is an automated response. For example, a message telling a customer that their email has been received and some will be in touch or the delivery of a brochure in response to a Web visitor filling in a request form.

A marketing email SNMP platform has more features, such as email editors that provide templates, and the ability to work through a database, filling in placeholder fields with personalized details. You can also get SNMP servers that only provide a testing service, providing a destination to which you can send emails when you are building an email application.

You might also see references to an SNMP relay. Effectively, all SNMP servers are relays. This just means that the server specializes in forwarding emails to the recipient’s email server, which is a function that all email servers perform, including all SMTP servers, other than those designed for testing. Within the industry, a provider that refers to SNMP relay means that the company will process very large numbers of emails that exceed the limit that most email providers impose.

Using a free SMTP server can significantly improve email deliverability compared to using standard PHP mail functions, which are often flagged as spam by major email providers. These servers typically offer features such as SSL/TLS encryption for secure email transmission, real-time analytics, and easy integration with various platforms. Additionally, many free SMTP servers provide user-friendly interfaces and customer support to help users set up and manage their email campaigns effectively.

The Best Free SMTP Servers

There are many SMTP server packages available and the majority of them offer a free plan, which is great for small businesses. There are so many that it will take you a long time to sift through all the options. So, we wrote this review to provide you with a shortlist to trial and save you time.

1. EmailSuccess

EmailSuccess offers a free plan designed for businesses needing a professional email delivery tool without licensing costs. It supports up to 100,000 emails per day and allows the use of two IP addresses. This on-premises solution is ideal for enterprises requiring high deliverability and advanced email management features.

Key Features:

• High deliverability: Ensures emails reach the inbox reliably.
• Advanced authentication: Supports SPF, DKIM, and DMARC.
• Adaptive email deliverability: Automatically tunes SMTP parameters.
• Enterprise-level performance: Handles high volumes of emails efficiently.
• Security and encryption: Full support for TLS encryption.

Why Do We Recommend It?

EmailSuccess is recommended for its high deliverability, advanced authentication, and adaptive email deliverability features. It’s an excellent choice for enterprises requiring a reliable, secure, and high-performance email delivery solution without initial licensing costs.

I found that apart from the Free plan, EmailSuccess offers Standard and Enterprise plans. The Standard plan allows unlimited emails and IP addresses, with specialized helpdesk support. The Enterprise plan includes integration with the MagNews campaign management platform, providing a comprehensive solution for high-volume email needs.

Who Is It Recommended For?

EmailSuccess is recommended for enterprises and businesses that require a high-performance email delivery solution. It’s particularly suitable for those requiring advanced email management features and high deliverability without the need for initial licensing investments.

The software for EmailSuccess will install on Windows or Linux; you can also choose to run the system over VMware, Hyper-V, or Docker. The free plan allows sending up to 100,000 emails per day and supports a maximum of two IP addresses. It includes all advanced features but lacks direct customer support, relying instead on community forums for assistance. Access the free tool even if you intend to go for a paid plan – you can use this as a free trial for assessment purposes.

3. SendGrid

SendGrid offers a free plan that is a solid option for individuals or small businesses needing a basic email service to handle up to 100 emails per day. It’s ideal for transactional emails, notifications, or small-scale email marketing. The platform is developer-friendly, offering APIs and integrations, while also providing essential email tracking and analytics features. The free plan is particularly useful for those assessing SendGrid’s services before upgrading to a paid plan.

Key Features: 

• A limited allowance of email throughput: 100 emails per day.
• An email API: Specifically for transactional emails.
• Email validation API: Ensures that the recipient address for the email is valid.
• Deliverability tools: SPF, DKIM, and DMARC to avoid spam filters.

Why Do We Recommend It?

We recommend the free plan of SendGrid for its ease of use, reliable email delivery, and access to developer tools like APIs, which allow for seamless integration into websites or applications. I noted that it’s a great way to explore their service without initial costs.

SendGrid offers scalable paid plans with varying features:

• Essentials Plan: Starting at $19.95/month for 50,000 emails/month.
• Pro Plan: Includes 100,000+ emails/month, dedicated IP, and enhanced security starting at $89.95/month.
• Premier Plan: Tailored for enterprises with custom pricing, advanced support, and high-volume sending.

Who Is It Recommended For?

SendGrid’s free plan is ideal for small businesses or startups sending fewer than 100 emails per day. It can also be useful for developers who need a quick, reliable transactional email service. Also, marketers testing email performance with low volume could use this free plan.

The most significant limitation of the free plan is the 100 emails per day cap, which may restrict growth or larger campaigns. Additionally, while it includes basic tracking and analytics, more advanced features—such as automation, dedicated IPs, and advanced deliverability tools—are locked behind paid tiers. You can access the Free plan with no obligations.

3. Elastic Email

Elastic Email’s free plan allows up to 100 emails per day. It combines email marketing tools and a straightforward API for developers. The platform provides basic email tracking and simple campaign creation features. Elastic Email’s free plan provides a great opportunity to test email campaigns and delivery services at no cost before upgrading to paid plans.

Key Features:

• 100 emails per day limit: Allows for small-scale email delivery or testing.
• Email API: Quick and easy integration for transactional emails.
• Basic email tracking: Monitor open and click rates for sent emails.

Why Do We Recommend It?

We recommend Elastic Email’s free plan for its easy-to-use interface and solid email delivery capabilities, making it a great option for those just starting out with email marketing or looking for a low-cost solution.

I learned that Elastic Email’s paid plans start with Email API at $15/month, offering 100,000 emails and advanced features like scheduling and priority support. The Marketing Plan, starting at $15/month, adds automation, advanced analytics, and segmentation. Larger businesses can opt for custom pricing, offering enterprise-level features, including dedicated IPs and enhanced support.

Who Is It Recommended For?

Elastic Email’s free plan is ideal for freelancers, startups, and small businesses who need to send limited emails while testing or experimenting with email marketing and transactional email services without spending upfront.

Elastic Email’s free plan limits users to 100 emails per day, restricting its use for larger campaigns. Additionally, advanced features like email automation, segmentation, in-depth analytics, and priority support are not included. Dedicated IPs are only available in higher-tier plans, which could impact deliverability for high-volume users.

4. Mailgun

Mailgun’s free plan is an excellent choice for developers and small businesses looking for a reliable, API-focused email delivery service. Primarily designed for transactional emails, Mailgun offers powerful features like advanced email analytics, SMTP relay, and a highly scalable infrastructure. The free plan provides 100 emails per day, making it suitable for testing and initial development. However, that plan does not include some advanced features like email validation and dedicated IPs, which are available on paid plans.

Key Features:

• Suitable for small-scale use: 100 emails per month.
• Email API: Fast and efficient email delivery, tailored for developers.
• SMTP relay: Easy email integration without setting up a full server.

Why Do We Recommend It?

We recommend Mailgun for its developer-friendly email API, reliable delivery, and easy scalability, making it an exceptional option for businesses needing transactional email services without high upfront costs.

I discovered that Mailgun offers paid plans, starting with the Basic plan that processes 10,000 emails for $15 per month. The  Foundation plan costs $35/month for 50,000 emails and basic support. The Scale plan starts at $90/month, offering 100,000 emails, enhanced security, and a dedicated IP.

Who Is It Recommended For?

Mailgun’s free plan is best suited for developers, startups, or small businesses looking to test or build transactional email services into their applications. It’s ideal for those who need a robust email API and don’t require extensive marketing tools.

Mailgun’s free plan offers 100 emails per month. Key features like email validation, advanced analytics, and dedicated IPs are excluded. This plan is primarily aimed at testing, with limitations making it less suitable for high-volume or long-term email marketing without upgrading to a paid plan.

5. Inboxroad

Inboxroad is a specialized SMTP relay service designed for high deliverability and performance, focusing on email marketing and transactional email services. Known for excellent email deliverability and reliable infrastructure, Inboxroad is aimed at businesses that require dedicated email servers and personalized support to ensure high inbox placement. Its services cater to businesses looking to send bulk emails.

Key Features:

• High deliverability: Focused on ensuring emails land in inboxes rather than spam folders.
• Custom SMTP relay: Easy integration with any email platform using SMTP.
• Dedicated support: Access to a personal account manager to optimize email delivery.

Why Do We Recommend It?

Inboxroad is recommended for its personalized support, which helps optimize email deliverability and sender reputation. Its dedicated SMTP services are particularly effective for businesses with high-volume email needs.

I observed that this service is based in the Netherlands and charges are levied in Euros. Above the Free plan, you will find the Basic edition (10,000 emails) at €25 per month, the Pro plan (100,000 emails) at €159 per month, and the Premium plan (1 million emails) at €1196 per month. All levels provide the same features.

Who Is It Recommended For?

Inboxroad is ideal for businesses that send large volumes of emails, such as email marketers, e-commerce platforms, and transactional email services, who require high deliverability and prefer dedicated IP services. It’s best suited for companies that value tailored support and custom solutions to optimize their email campaigns.

Inboxroad offers a standard free plan that includes all the features of the lower paid plan, which is called Basic. The Free edition is primarily intended for businesses to test the platform’s deliverability and features before committing to a paid plan.

6. Postmark

Postmark is a high-performance email delivery service designed for transactional emails, emphasizing speed and reliability. While Postmark does not offer a traditional free plan, every account gets 100 emails processed for free each month, so if you don’t go over that level, you never have to pay. Postmark focuses on transactional emails like password resets, purchase confirmations, and notifications rather than bulk marketing emails. Its deliverability is exemplary, and detailed email tracking is useful for system testing feedback.

Key Features:

• Fast email delivery: Transactional emails are prioritized for speed, ensuring prompt inbox placement.
• 100 email free trial: Allows new users to test the platform before committing.
• Email API: Developer-friendly API for seamless integration with applications.

Why Do We Recommend It?

Postmark is recommended for its speed and reliability in delivering transactional emails, making it perfect for businesses that need crucial emails to land in inboxes immediately. Its developer-friendly API is an additional plus.

I noted that Postmark’s paid plans are straightforward and based on email volume. The paid plan starts at $15/month for 10,000 emails. Dedicated IPs are available starting at $50/month for high-volume users, improving sender reputation and deliverability.

Who Is It Recommended For?

Postmark is ideal for developers, SaaS platforms, e-commerce businesses, and startups that require fast and reliable transactional email services. It’s best suited for businesses that focus on email notifications, password resets, and order confirmations, rather than bulk email marketing.

Postmark offers 100 emails for free each month. Users pay for usage above that level. Postmark’s essential features include fast delivery and detailed email tracking, but it cannot be used for bulk email marketing. Features like dedicated IP addresses and higher email volumes are only available in paid plans.