Mor MesterIn this article, we’ll discuss the best free SMTP servers. With so many options out there, it can be tough to know where to start. We’ll go over the features and benefits of each free SMTP server so you can decide which one is right for you.
What is an SMTP server?
SMTP, or Simple Mail Transfer Protocol, is a system to send and receive email. It uses a set of rules to decide how email should be sent over the internet. An SMTP server is a computer that handles the sending and receiving of email messages.
How do SMTP servers work?
To use an SMTP server, you must have an email address and be able to connect to the internet. When you send an email, it will be routed through the SMTP server to reach its destination.
Similarly, when you receive an email, it will be delivered to your inbox via an SMTP server. While there are other ways to send and receive an email, SMTP is by far the most popular method.
The difference between SMTP and SMTP relay server
SMTP servers and SMTP relay servers both help the delivery of emails, but they differ in how they handle outgoing messages.
An SMTP server is typically used by individual users to send emails from their personal accounts to a recipient’s inbox.
While an SMTP relay server is used by organizations to send large numbers of emails, such as a monthly newsletter, order confirmation emails or other transactional emails.
An SMTP server requires each user to authenticate their identity before sending messages, an SMTP relay server does not. As a result, spammers often use SMTP relay servers to send unsolicited emails.
Because of this, most email providers need users to configure their SMTP settings before they can use an SMTP relay server.
Advantages of an SMTP service
There are many advantages that an SMTP service can offer.
An SMTP service can help to improve your email deliverability. Your messages are more likely to reach their intended recipients, and they’re less likely to get caught in spam filters.
An SMTP service can provide valuable insights into your emails’ performance. You can fine-tune your email strategy for the most impact with detailed reports on open rates, click-through rates, and other metrics.
And for those times when you need to send out many emails, an SMTP service can make the process much easier. Saving you time and hassle.
The 11 Best Free SMTP Servers in 2025
The following are the best free SMTP servers you can use for sending emails:
1. SMTP2GO
SMTP2GO has you covered with setting up and managing your outgoing emails. Their easy-to-use tools and a multi-datacenter infrastructure make sure your email delivery is always reliable. Plus, their free plan offers 1000 emails per month, so you can get started without any upfront costs.
SMTP2GO offers a unique set of features that makes it the ideal choice for those who need to send emails on a regular basis. For starters, the advanced email testing options let users test their messages before sending them.
Real-time email reports provide users with valuable feedback on the performance of their messages, letting you make necessary adjustments to improve results.
The easy-to-use API makes it possible for users to integrate SMTP2GO into their existing stack with ease. Developers need to put in minimum effort and there are no rate limits for any API calls.
2. Brevo
Brevo is a free SMTP service with 300 emails daily without any costs. It’s a popular choice for email marketing, marketing automation, and transactional emails
Brevo’s SMTP features are designed to get your emails delivered with a 99.8% deliverability rate. This free SMTP service provider has a flexible API for creating custom and dynamic email messages.
Brevo’s reports give insights into your email performance, including open, click, and deliverability rates. Brevo’s simple integration with popular apps makes it one of the best free SMTP service providers.
3. Mailersend
MailerSend‘s SMTP relay service is a simple, reliable way to send transactional emails quickly and at scale. With 3000 emails included in the free plan, and a 99.5% uptime SLA, you can be confident that your emails will be delivered on time, every time.
Whether you’re sending customer purchase receipts, password reset instructions, or shipping notifications, MailerSend’s SMTP relay service will ensure that your messages reach their recipients.
Its email API allows users to send emails through its SMTP relay, which includes support for webhooks.
MailerSend’s suppression management system keeps bounce rates low and their reputations high. This is useful for managing email deliverability.
The service provides detailed tracking and analytics reporting so that users can track the performance of their campaigns.
MailerSend’s bulk emailing feature makes it easy to send large numbers of emails at once. This makes it an ideal choice for businesses that need to send high volumes of transactional emails.
4. NetCore (formerly Pepipost)
If you’re looking for a reliable SMTP email delivery service, NetCore is an option. You can connect it to any app or service, including your website with their WordPress plugin. With NetCore STMP, you can send up to 100 emails per day for free and up to 30,000 emails during your first month.
Netcore SMTP is a reliable, scalable, and secure email delivery platform that offers AI-backed email delivery, custom email tracking, and Subaccount Management.
With AI-backed email delivery, Netcore SMTP improves your deliverability rate by detecting and correcting any errors in your email before it is sent. This can save you time and money by avoiding costly bounces and spam reports.
See detailed information about each email, including when it was opened, how many times it was forwarded, and whether any links were clicked. This is useful for understanding engagement rates and determining which emails are most popular with your audience.
Netcore SMTP’s Subaccount Management feature makes it easy to keep track of multiple accounts. This can be helpful if you have a team of employees who need to access different parts of your account.
Netcore SMTP is a powerful email delivery platform that offers some great features. It’s an easy contender for the best free SMTP server.
5. Gmail SMTP Server
Gmail is a free SMTP server that allows you to send up to 500 emails a day. Upgrade your Gmail account with a Google Workspace subscription to send 2000 daily emails.
It’s also easy to use, with a simple interface that is easy to navigate. Gmail has a variety of features, such as inbox organization, spam filtering, and search. You can also access Gmail from any device, including your mobile phone or tablet. Check out our list of Gmail productivity tips to become a power user in no time.
Google SMTP server has two important features that make it a reliable choice for email delivery:
- It doesn’t use port 25 to start an SMTP session. This reduces the chances that your message will be blocked by spam filters.
- Google’s servers are designed to provide a backup in case your primary SMTP server is unavailable. As a result, you can be sure that your messages will be sent even if there are problems with your main server.
6. SendGrid
SendGrid is a cloud-based SMTP provider that allows you to send emails through their network. They offer a free plan with 100 emails per day. Their service is used by major companies, including Uber, Spotify, Instacart, and Airbnb.
SendGrid offers a variety of features, including a drag-and-drop email builder, real-time analytics, and API access. They also offer 120+ integrations, making it easy to use their service with the software you already use.
SendGrid’s email validation is one of its best features. It cleans your email list to make sure you only send to valid email addresses that won’t bounce.
This SMTP relay service also offers integration and access to comprehensive open-source libraries in 7 programming languages. With this, you can integrate SendGrid into your existing infrastructure. And, if you’re not a developer, you can still sign up to SendGrid and use the visual interface to start sending emails.
7. Amazon SES
Amazon Simple Email Service (SES) is a cost-effective, flexible, and scalable email service for marketing and transactional emails. With Amazon SES, you can send transactional emails, such as order confirmations and password reset emails, to your customers. You can also send marketing emails, such as product recommendations and special offers, to your subscribers.
Get started with the Amazon SES free plan, which gives you 62,000 emails per month for sending emails.
One of the best features is the sender configuration options. This allows you to specify the AWS Regions that you want to use for sending emails. And which Amazon SES endpoints to use.
Another great feature is the sender identity management and security. Amazon SES gives options for verifying identities, including email addresses, domains, and IP addresses.
Amazon SES offers many email security features, such as TLS encryption and DKIM signing. They also provide detailed sending statistics. The Deliverability Dashboard shows you information about your emails, such as delivery rates, complaint rates, and bounce rates. This information can be very helpful in troubleshooting deliverability issues.
8. Mailgun
Mailgun is an email service that comes with 5000 emails per month in their free trial. After the trial, they have 3 paid plans starting at $35/month and going up to $90/month.
Send and receive emails using their web interface or your own custom applications with their email APIs. With their SMTP Relay feature, you can use their servers to relay emails from your own mail server. Check out this full Mailgun review to learn about its features, pros, cons, and pricing.
Use the Webhooks feature to receive real-time notifications when certain events happen. Such as when an email is opened or a link is clicked.
Mailgun’s premium SMTP server also offers:
- 99.99% Guaranteed Uptime
- 24/7 support
- Email tracking and reports
- Suppression management
9. Postmark
Postmark is a transactional email service provider known for its focus on delivering high-quality transactional emails. They provide a very good free SMTP relay service with 100 emails per day. Their paid plans range from $10 to $400.
Postmark’s top features include developer-friendly SMTP documentation, SMTP service endpoints in AWS Regions around the world, and advanced email analytics.
The documentation makes it easy to integrate Postmark into your application, and the service endpoints guarantee high availability and low latency. The advanced email analytics give you insight into your email delivery, including bounces, clicks, opens, and more.
10. Mailjet
Mailjet is an SMTP solution that you can use for both marketing emails and transactional emails. You can send up to 200 emails per day with the free SMTP sending service. The paid plans for this start at $15 per month.
The free plan still includes useful features like unlimited contacts, APIs, SMTP relay, webhooks, and an email editor. For the top standalone editors, check out our list of the best drag and drop email template builders.
Mailjet could be a great solution for your email needs whether you are looking to send out a mass marketing campaign or just want to keep in touch with customers on a more personal level.
11. Spark Post
Sparkpost is a cloud-based SMTP service provider with plans starting at $9/month. And best of all, they offer a free plan that includes 15,000 emails/month. They have customers like Mailchimp, The New York Times, and Twitter.
Some of its best features include 35 real-time email metrics, high deliverability rates, and a developer-friendly interface.
With these features, you can see how your email campaigns are performing and make necessary adjustments on the fly. You can also be confident that your emails will reach their intended recipients and not land in the spam folder. You’ll be able to take full advantage of Spark Post’s powerful SMTP services.
Wrap up: The best SMTP servers
The best SMTP providers offer a reliable way to send emails. They come with a variety of features, including support for multiple email accounts, a user-friendly interface, and the ability to customize messages. With the services we’ve talked about in this piece, you are sure to find a free server that meets your specific requirements.
Looking for the best email marketing platforms that do much more than just sending? Check out our reviews of the most popular tools:
Rukham Khan
Jenny Sharp
