Top 10 Best Free SMTP Servers

Email marketing is crucial for businesses to reach their target audience and boost engagement. SMTP services provide a reliable and efficient method for sending mass and transactional emails. This article compares top providers to help businesses make informed decisions.

Top 10 Best Free SMTP Servers

Email marketing has become an essential tool for businesses looking to reach their target audience and increase engagement.

With the rise of digital communication and e-commerce, it is crucial for companies to have a reliable and efficient method of sending emails. This is where SMTP (Simple Mail Transfer Protocol) services come in.

SMTP services allow businesses to send mass emails, transactional emails, and other types of email communications easily and securely. These services use SMTP servers to deliver emails to the recipient's inbox.

While there are many SMTP service providers on the market, it can be overwhelming for businesses to choose the best one for their needs.

In this article, we will compare some of the top SMTP service providers.We will look at their unique selling propositions, features, pricing tiers, customer support, and more. This comparison will help businesses make an informed decision when choosing the right SMTP service for their email marketing needs. 


Maileroo emerges as a contender in the SMTP service market by prioritising ease of integration and affordability.

Positioned for small to medium-sized businesses, Maileroo offers a seamless setup process, allowing companies to quickly implement its SMTP solutions without extensive technical knowledge.

Key features and benefits:

    • Simplified Integration: Maileroo's straightforward API and SMTP relay options cater to non-technical users, ensuring a smooth setup.
    • Cost-Effective Pricing: With tiered plans based on email volume, Maileroo provides an economical solution for businesses mindful of budget constraints.
    • Dedicated IPs: For enterprises seeking to elevate their emailing capabilities, Maileroo offers dedicated IPs. This feature changes everything for senders who send a lot of emails. It gives the email infrastructure the boost it needs to be strong and reliable.
    • Sender Authentication: Maileroo puts protecting your sender's reputation first. With DKIM, SPF, and DMARC, the platform makes sure that your emails are real, which lowers the chance of being marked as spam and improves deliverability.
    • 24/7 Support: Regardless of the plan selected, all users have access to around-the-clock customer service, ensuring issues are promptly addressed.
    • Analytics and Reporting: Users can track email delivery rates, bounces, and open rates through Maileroo's intuitive dashboard, allowing for informed strategy adjustments.
    • Transparent Pricing: Maileroo's pricing is made to work for a lot of different types of users. You can choose from a variety of plans at Maileroo, ranging from the free plan for beginners to the enterprise plan for large businesses.

Limitations and considerations:

    • Limited Advanced Features: Compared to other providers, Maileroo might offer fewer advanced features, which could be a drawback for businesses with complex email marketing needs.
    • Growing Pains: As a relatively new player, Maileroo is in a growing phase, which might lead to evolving service offerings and adjustments in its platform.

Maileroo's focus on simplicity and affordability makes it an attractive option for startups and small businesses venturing into the realm of email marketing without the desire or resources to invest heavily from the outset.


Brevo, formerly known as SendInBlue, stands out in the crowded email marketing solution space by offering a solid SMTP server that facilitates not just email campaigns but also transactional emails, automations, and SMS messages. 

This versatility is particularly beneficial for businesses looking to engage their audience through multiple channels. Unique to Brevo, users can create marketing workflows that trigger emails based on specific user actions, enhancing personalisation and engagement.

Brevo offers a comprehensive set of advantages for businesses intent on refining their email marketing strategies. Notably, it provides:

  • Advanced Segmentation: This feature allows businesses to categorise their contacts into highly targeted groups based on behaviour, preferences, and previous interactions, which can significantly increase the effectiveness of campaigns.
  • Integrated Marketing Automation: SendInBlue's marketing automation capabilities are designed to save time while increasing the precision of email campaigns, enabling businesses to send messages triggered by specific criteria.
  • High Deliverability Rates: Ensuring emails actually reach inboxes, SendInBlue focuses on maintaining high deliverability rates, which is critical for the success of any email marketing effort.

Pricing and Limitations

Brevo's pricing model is designed to scale with the needs of businesses, offering a free tier with basic features and paid plans that expand capabilities according to the volume of emails sent.

However, while the platform is dynamically suited for businesses of various sizes, those requiring more niche or advanced features may find limitations in the customisation options available. 

Moreover, some users may find the interface less intuitive than on similar platforms, potentially requiring a steeper learning curve.


Mailgun sets itself apart with its set of features designed for developers and businesses aiming for efficiency and scalability in their email operations. Their key features include:

  • Reliable Email Delivery: Mailgun emphasises its powerful delivery infrastructure, ensuring high deliverability rates for transactional and marketing emails.
  • Detailed Analytics and Tracking: They let users watch the success of their emails with detailed reports on opens, clicks, and bounces in real time. This lets users make decisions based on data.
  • Flexible Email APIs: Mailgun focuses on the needs of developers by offering adaptable APIs that can be easily integrated into current systems. This makes it possible to create automatic and personalised email solutions.

Use Cases and Integrations

Mailgun caters to a range of use cases, from transactional emails, such as receipts and notifications, to marketing campaigns and automated messaging sequences. 

It works with many programming languages and frameworks and can connect to well-known platforms like WordPress and Zapier. This makes it a good choice for companies that want to automate and connect their email processes to make them more efficient.

Pricing and Limitations

While Mailgun offers a set of features for managing and sending emails, it's important to be aware of its limitations. 

One notable limitation of Mailgun is its complexity in initial setup and configuration for those without technical expertise, potentially requiring additional resources or support to get started. 

Also, its pay-as-you-go pricing model, although competitive, can escalate quickly for businesses with high email volume, making it less cost-effective for larger scale operations. 

While Mailgun provides detailed analytics and logs, navigating and interpreting this data can be overwhelming for users unfamiliar with such detailed reporting. There are occasional reports of deliverability issues, especially with emails landing in the spam folder, which could be a concern for businesses relying heavily on email communication.

Amazon SES

Amazon Simple Email Service (SES) is another email delivery solution that is designed to help businesses send transactional, marketing, and notification emails. It is recognised for its high deliverability rates, ensuring that emails make it to the intended inboxes. 

Here's a closer look at the key features that make Amazon SES:

  • Scalability and Reliability: Amazon SES is built on the highly scalable infrastructure of AWS, allowing it to handle any volume of email without compromising on performance. 

Amazon's well-known data centres support its dependability, ensuring that your email communication is reliable and consistent.

  • Competitive Pricing Model: With a pay-as-you-go pricing strategy, Amazon SES is known for its cost-effectiveness, especially for businesses with large volumes of emails. 

This model allows companies to pay only for what they use, making it an economical option for startups and large enterprises alike.

  • Integration Capabilities: Amazon SES integrates with other AWS services, providing a comprehensive ecosystem for application hosting, data storage, and more. 

Its API flexibility also enables easy integration with existing applications, making it a versatile tool for enhancing your email communication strategy.

Pricing and Limitations

Amazon SES offers a pay-as-you-go pricing model, with no upfront costs or long-term commitments, meaning customers only pay for what they use.

 This can be particularly advantageous for startups and small businesses looking to keep their operating costs low. 

However, similar to other SMTP services, Amazon SES has its limitations. The service enforces strict sending limits to protect the platform’s reputation and maintain high deliverability rates. 

And even though SES has a high deliverability rate, more complex email campaigns may need extra software or custom development work because of its simple interface and lack of built-in marketing tools. This could increase complexity and costs for users requiring more than the basic email functionalities.


SendGrid is a great option for businesses that want an email delivery service with a lot of features that make sure emails get delivered, the ability to connect to many other services, and a lot of customer support and resources.  

SendGrid's main goal is to improve email deliverability, making sure that transactional and marketing emails get to the right people without getting caught by spam filters.

  • Comprehensive Deliverability Features: They provide detailed analytics on emails sent, opened, and clicked, allowing businesses to fine-tune their email campaigns for maximum impact. 

Features such as dedicated IP addresses and domain authentication tools further enhance deliverability rates.

  • Integration with Other Services: The platform excels in its ability to integrate smoothly with a range of applications and services. 

Whether it's CRM systems or web applications, SendGrid’s flexible APIs and webhooks make integration straightforward, streamlining the process of syncing email capabilities with existing systems.

  • Customer Support and Resources: SendGrid knows how complicated email marketing and transactional email delivery can be, so they offer a lot of resources, such as guides, tutorials, and a knowledge base.

Moreover, their customer support team is readily available to assist with any queries or issues, ensuring businesses can maximise the effectiveness of their email communication strategies.


Postmark stands out for its unwavering commitment to performance and deliverability. Their system was made for developers and businesses that need their transactional emails to get to their inbox quickly and reliably. 

Here are some of the notable perks you can get from Postmark:

  • Focused on Transactional Emails: Postmark's singular focus on transactional email sets it apart, ensuring that crucial emails such as password resets, order confirmations, and welcome messages are delivered without delay.
  • Performance and Deliverability: With a strong infrastructure optimised for speed and reliability, Postmark boasts industry-leading deliverability rates. 

Their proactive approach to maintaining a reputable sending status translates into unmatched email performance.

  • Unique Selling Propositions: Among its key advantages, Postmark offers an intuitive and user-friendly interface, detailed analytics and insights, a dedicated IP address for each account, authentication options such as SPF and DKIM, and advanced features like bounce management and inbound parsing.
  • Flexible Pricing Plans: Postmark's pricing model is based on the number of emails sent per month rather than the number of contacts or subscribers, making it suitable for businesses of all sizes. Custom plans are also available for high-volume senders.
  • Expert Support: Postmark's team of email delivery experts is committed to providing timely, personalised support to ensure that customers get the most out of their service. 

They also offer helpful resources and guides on best practices for transactional emails. 

Pricing and Limitations

In terms of pricing, Postmark adopts a straightforward approach, offering a range of plans tailored to different volume needs. 

The starting plan allows users to send 10,000 emails per month for a set fee, with the cost per email decreasing as volumes increase. This makes it an economically viable option for both small and large businesses. 

They also provide a unique feature in the form of "message streams," which helps in segregating transactional and marketing emails, ensuring high deliverability by maintaining the sender's reputation.

Nonetheless, Postmark’s focused specialisation on transactional emails may be a limitation for businesses seeking a more all-encompassing email marketing solution. It lacks the broader marketing tools found in platforms like SendGrid, such as extensive design templates and automation capabilities for marketing campaigns. 

Consequently, businesses might need to incorporate additional tools or services for their marketing emails, potentially complicating their workflow and increasing operational costs. Moreover, their services also come with a higher price point compared to some competitors, which could be a consideration for cost-conscious companies.

Mandrill by Mailchimp Integration

Mandrill, a transactional email platform by Mailchimp, integrates with Mailchimp's marketing platform, enabling businesses to unify their email marketing campaigns and transactional email. 

This integration allows for a cohesive branding experience across all forms of email communication, making it easier for businesses to manage their emails from a single interface. 

Users can easily design transactional emails using Mailchimp's creative tools and track both marketing and transactional emails' performance in one place.

Features and Analytics

Mandrill offers a set of features designed to optimise email delivery and engagement. This  includes detailed analytics that provide insights into email performance, such as open rates, click rates, and bounce rates. 

Users can also access advanced analytics to track geography, device usage, and more, enabling businesses to tailor their communications based on real data. 

Mandrill also supports A/B testing, allowing users to test different email templates and messages to determine the most effective strategy.

Pricing and Limitations

Mandrill's pricing model is built with flexibility in mind, catering to businesses of all sizes. 

The plan is based on the number of emails sent, with volume discounts available for larger senders. This pay-as-you-go approach ensures that businesses only pay for what they need, providing significant value. 

However, Mandrill’s limitations are evident when considering its dependency on a Mailchimp account for operation, potentially alienating users looking for a stand-alone transactional email service. This integration with Mailchimp means businesses looking for a more diversified or independent platform might find Mandrill restrictive.


SparkPost is a cloud-based email delivery service that specialises in the reliable delivery of high-volume emails. 

It provides businesses with predictive analytics and insights, enabling them to optimise their email strategy effectively. 

Their technology is designed to offer superior email deliverability, ensuring that emails reach their intended recipients' inboxes. .

Comparison with Other SMTP Services

SparkPost sets itself apart with its predictive email intelligence and customer-centric optimisation strategies. 

Businesses often find SparkPost's detailed analytics invaluable for enhancing email strategies, something that not all competitors may provide with the same level of depth or accuracy. 

They also place emphasis on security, and its ability to scale with growing email volumes makes it a go-to choice for organisations prioritising reliable email communication.

Pricing and Limitations

SparkPost adopts a tiered approach, offering both a free starter plan for basic needs and more advanced plans catering to higher volume senders. 

This structure allows businesses to scale their email operations as they grow, ensuring they only pay for what they need. 

However, there are still potential limitations with SparkPost, including a steep learning curve for its more advanced features and a possible need for technical expertise to fully utilise its robust capabilities. 

While the platform's feature set is a significant advantage, smaller businesses or those with simpler emailing needs might find SparkPost's offerings more complex than necessary, leading to underutilization of the service.


SMTP2GO provides a user-friendly interface that simplifies the email setup process, making it accessible for businesses of all sizes. Users can set up their email systems quickly and easily with clear documentation and step-by-step guides. This cuts down on downtime and technical problems. They made sure that even users with limited technical knowledge could manage their email communications effectively.

Another strength of SMTP2GO is its dedicated customer service and support team. Available 24/7 through various channels, including email, live chat, and phone, the support team is committed to resolving any issues promptly. 

Pricing and Limitations

SMTP2GO offers a range of pricing tiers designed to accommodate the needs of different businesses, from small startups to large enterprises. Each tier provides various features and capabilities, ensuring that businesses can select the plan that best matches their email volume and requirements. 

One of the primary concerns is its feature set, which, while sufficient for basic email sending needs, may lack the advanced customisation and integration capabilities that larger enterprises or tech-heavy users might seek. 

Although SMTP2GO provides analytics, users looking for deeper email performance insights might find the data somewhat limited compared to more comprehensive platforms. These constraints suggest that while SMTP2GO is an excellent choice for those prioritising ease of use and reliable delivery, businesses requiring extensive analytical tools or sophisticated automation might need to explore additional options.

Pepipost by Netcore

Pepipost prioritises the speed and security of email delivery, ensuring that emails not only reach their recipients swiftly but are also protected against potential threats. 

This commitment to fast and secure delivery is achieved through advanced infrastructure and robust security measures, making Pepipost a reliable partner for businesses concerned with maintaining the integrity and confidentiality of their email communications.

Pricing and Limitations

Pepipost offers pricing benefits, including a generous free tier designed for startups and small businesses. This free tier allows companies to send a significant number of emails per month without incurring costs, providing an economical yet powerful solution for managing email communications.  

However, some users have noted that Pepipost's user interface lacks intuitiveness and can be cumbersome to navigate. This may pose a challenge for those who are not technologically savvy. Also, customers have reported delays in receiving assistance, which could impact businesses relying on timely communication. 

Factors to Consider When Choosing an SMTP Server

When selecting an SMTP server for your business, several critical factors should be evaluated to ensure efficient and secure email communication.

Reliability and uptime are important, as they determine the server's ability to remain operational and available for sending emails without interruptions. A server with high reliability and uptime guarantees minimal disruption in email communications, which is essential for maintaining business continuity.

Deliverability rates are also very important because they determine whether your emails get to the inboxes of the right people or get filtered out as spam. A higher deliverability rate increases the chances of your messages being seen and read.

Security features protect your email communications from unauthorised access and potential cyber threats. Choosing a server with strong security features like encryption and spam filters will protect the privacy and integrity of your email conversations.

Scalability is essential for accommodating the growing needs of your business. A scalable SMTP server can handle more emails as your business grows, without slowing down or losing its reliability.

The ease of integration is pivotal for a seamless workflow. An SMTP server that offers straightforward integration capabilities can save your team time and effort, ensuring a smooth transition and operation.

Taking these things into account will help you pick the best SMTP server for your business, making sure that email communication is quick, safe, and reliable.

Wrap Up

Selecting the right SMTP server for your business’ needs involves a careful assessment of various critical factors such as reliability, deliverability rates, security, scalability, and ease of integration. 

These top free SMTP servers offer a viable starting point for businesses seeking cost-efficient solutions without sacrificing quality. 

However, every business has unique needs, and what works for one may not work for another. 

We encourage you to explore a range of options, including Maileroo, to find the perfect blend of features that align with your business requirements. 

Experimenting with different SMTP servers can reveal the best fit, ensuring your email communications are not just efficient and secure but also enough to grow with your business.