Email sent from a website looks simple from the outside. A customer submits a form, an order gets confirmed, or a password reset arrives seconds later. Behind that small interaction sits an SMTP server responsible for moving the message to its destination.
Running a mail server independently is possible, but it brings extra work. IP reputation, authentication, bounce handling, spam complaints, and server maintenance quickly become a headache. A free SMTP server removes much of that burden.
The best free SMTP servers provide enough sending capacity for small websites, development projects, WordPress sites, SaaS testing, and low-volume transactional email. Some also include APIs, logs, analytics, and domain authentication.
Here are 10 options worth considering.
1. Brevo
Brevo is one of the more generous choices for small businesses that need SMTP without paying from day one.
Its free plan allows up to 300 emails per day and has no expiry date. SMTP relay and API access are included, making the service suitable for website notifications, account confirmations, receipts, and similar transactional messages.
Brevo also supports SPF, DKIM, and DMARC authentication. Tracking, analytics, webhooks, contact management, and email-building tools are available alongside SMTP.
Free allowance: 300 emails per day
Best suited for: Small websites, WordPress and transactional email
The daily restriction is the main catch. Unused sends do not roll over, so a sudden campaign cannot use several days of accumulated capacity.
2. Mailjet
Mailjet combines an SMTP relay with email marketing and developer tools. The free account currently includes 6,000 emails each month, although sending is capped at 200 emails per day.
SMTP relay, APIs and webhooks are available without moving to a paid subscription. Basic statistics also make it easier to see whether messages were delivered, opened, or clicked.
There is another useful detail: the free plan does not require a credit card at signup. For testing a new website or application, that removes unnecessary friction.
Free allowance: 6,000 emails per month, 200 per day
Best suited for: Small applications and mixed transactional/marketing use
3. Mailtrap
Mailtrap started out with a strong reputation among developers for email testing, but its Email API/SMTP product can also send real transactional messages.
The free Email API/SMTP plan currently provides 4,000 emails per month with a 150-email daily limit. It includes one sending domain and three days of email logs.
Mailtrap becomes particularly useful during development because testing and production sending can sit within the same platform. Developers can inspect email behaviour before messages ever reach real customers.
Free allowance: 4,000 emails per month, 150 per day
Best suited for: Developers, staging environments and transactional applications
Do not confuse its Email Sandbox allowance with its production SMTP allowance. They are separate products with different limits.
4. Resend
Resend takes a developer-first approach to transactional email. The interface is clean, setup is relatively quick, and SMTP support means an application does not have to use Resend’s API directly.
Its free tier includes 3,000 emails per month with a maximum of 100 per day. Up to three domains can be used, and the plan includes 30-day data retention and ticket support.
Those limits make Resend a practical match for smaller SaaS applications, side projects, authentication emails and automated notifications.
Free allowance: 3,000 emails per month, 100 per day
Best suited for: SaaS projects and developer-led applications
5. SMTP2GO
As the name suggests, SMTP2GO concentrates heavily on outgoing email delivery.
The free account provides 1,000 emails each month and permits up to 200 emails per day. Accounts without a verified sender domain also face a 25-email-per-hour restriction. Verifying the sending domain removes that hourly restriction.
The service offers reporting and straightforward SMTP integration, so existing applications can switch from a hosting provider’s mail server without major code changes.
Free allowance: 1,000 emails per month, 200 per day
Best suited for: Websites, devices and applications needing a straightforward SMTP relay
6. MailerSend
MailerSend is built around transactional email and provides both an Email API and SMTP relay.
Its free plan currently includes 500 emails per month with a 100-email daily limit. One domain, one SMTP user, webhooks, tracking, multiple email editors and real-time activity tools are included.
Five hundred messages will disappear quickly on a busy website. For a portfolio site, internal tool, prototype or low-volume application, however, the allowance may be perfectly adequate.
Free allowance: 500 emails per month, up to 100 per day
Best suited for: Testing and small transactional projects
7. Postmark
Postmark focuses on transactional rather than bulk promotional email. That makes it particularly relevant for password resets, receipts, account alerts and application notifications.
Postmark offers a Free Developer plan capped at 100 emails per month. There are no overages on that plan, so sending stops once the allowance has been consumed.
The quota is tiny compared with Brevo or Mailjet. Still, a developer testing an integration may care more about a stable transactional-email environment than raw volume.
Free allowance: 100 emails per month
Best suited for: Development and low-volume transactional testing
8. Twilio SendGrid
Twilio SendGrid remains a familiar name in cloud email delivery, although its free offering is now a trial rather than a permanent free SMTP plan.
New trial accounts can send up to 100 emails per day through the Email API or SMTP for 60 days. Sending stops after the trial unless a suitable paid Email API plan is selected.
That makes SendGrid more useful for evaluating an SMTP provider than for permanently running a zero-cost production service.
Free allowance: 100 emails per day for 60 days
Best suited for: Short-term testing before choosing a paid provider
9. Amazon SES
Amazon Simple Email Service (SES) deserves a place here, but its free model changed in 2026.
Amazon ended the SES-specific 3,000-message monthly free tier for new customers in July 2026. New AWS customers can instead receive up to $200 in AWS Free Tier credits, available for six months on the free AWS plan, and those credits can be applied toward SES.
SES supports SMTP as well as API-based sending. Its pricing after free credits is usage-based, making it attractive when a project eventually grows beyond free allowances.
Free offer: AWS Free Tier credits for eligible new customers
Best suited for: AWS-hosted applications and developers expecting to scale
10. Gmail SMTP
Gmail can act as an SMTP server for very small-scale requirements. Applications such as WordPress can authenticate with a Google account and send mail through Google’s SMTP infrastructure.
It works best for contact-form messages, personal projects, testing and other low-volume tasks. Gmail accounts have sending restrictions and anti-abuse controls, so the service should not be treated as a bulk transactional email platform.
For business-critical applications, a purpose-built SMTP provider offers better logging, domain management, bounce handling and scaling.
Free option: Available with a standard Gmail account, subject to Google sending limits
Best suited for: Personal sites and very low-volume sending
How to Choose a Free SMTP Server
Sending allowance should not be the only deciding factor. A service offering thousands of messages means little if its daily cap blocks normal traffic.
Check several points before connecting a website:
- Monthly and daily limits: Estimate both normal traffic and short-term spikes.
- SMTP authentication: Credentials should be protected and rotated when required.
- Domain authentication: SPF, DKIM and DMARC help receiving systems verify legitimate mail.
- Logs: Delivery records make failed emails far easier to investigate.
- Bounce handling: Repeatedly sending to invalid addresses damages sender reputation.
- Upgrade costs: A free SMTP server can become expensive once traffic grows, so paid pricing deserves attention early.
Transactional and marketing email should also be treated differently. Password resets and purchase receipts require prompt delivery. Newsletters usually have less urgency but much greater volume.
Final Thoughts
There is no single free SMTP server that fits every website. Brevo and Mailjet provide generous ongoing allowances, while Mailtrap and Resend are attractive for developer-focused projects. SMTP2GO keeps traditional SMTP relay simple. MailerSend and Postmark suit smaller transactional workloads.
SendGrid is better viewed as a time-limited trial today, while Amazon SES makes more sense for projects already tied to AWS. Gmail can cover basic personal-site requirements, but it is not a replacement for dedicated transactional email infrastructure.
Start with expected sending volume, then examine daily limits, authentication, logs and future pricing. A free SMTP service should solve today’s delivery problem without creating a bigger one when traffic begins to climb.
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