Last updated: January 8, 2026

If your emails aren’t reaching inboxes—or your app/website is sending messages unreliably—switching to a dedicated SMTP server (or SMTP relay) is often the fastest upgrade you can make. In this guide, you’ll find the best free SMTP servers in 2026, including forever-free tiers, generous developer plans, and a self-hosted option for full control.

Important: “Free SMTP” usually means a free tier with monthly/daily limits, not unlimited sending. Also, most free plans are best for transactional email (password resets, OTPs, receipts), not bulk newsletters or cold outreach.

Key Takeaways

• Use SMTP relays for reliability: They handle deliverability infrastructure, feedback loops, and scaling better than basic hosting mail.
• Authenticate your domain: Set up DMARC, SPF, and DKIM to reduce spam-folder placement.
• Free tiers are best for small apps: Perfect for MVPs, staging environments, low-volume SaaS, and WordPress contact forms.
• Watch the limits: Many plans cap daily sends (e.g., 200/day or 300/day) even if monthly limits look high.
• For WordPress: Pair your SMTP service with a reliable plugin like WP Mail SMTP and test sending before going live.

Table of Contents

What is an SMTP server (and SMTP relay)?

SMTP (Simple Mail Transfer Protocol) is the standard protocol used to send email across the internet. When people say “SMTP server,” they usually mean one of these:

• SMTP relay service (most common today): A provider gives you SMTP credentials (host, port, username/password) and sends emails on your behalf. This is what most “free SMTP servers” in this list are.
• Self-hosted SMTP server: You run mail software (like Postfix) on your own VPS/server and manage deliverability, IP reputation, and anti-spam settings yourself.

If you’re building a website, SaaS, mobile app, or WordPress site, an SMTP relay is typically the best mix of reliability + speed + deliverability without the pain of self-hosting.

Helpful explainer: What is an SMTP server?

Who should use free SMTP servers?

Free SMTP servers are ideal for:

• Startups & MVPs sending password resets, OTPs, sign-up confirmations, and invoices
• WordPress websites that need contact form delivery and order emails that actually arrive
• Developers who need staging/testing email for apps
• Small businesses with low-volume transactional needs

They’re usually not ideal for high-volume newsletters or cold email campaigns. For newsletters, consider dedicated email marketing platforms (with consent-based lists and built-in unsubscribe compliance).

How to choose the best free SMTP server

Before you pick a provider, evaluate these criteria:

1) Free plan limits (daily vs monthly)

Some platforms advertise a monthly allowance but enforce a strict daily cap (e.g., 200/day). If your app sends bursts (password reset spikes), daily limits matter.

2) Domain authentication & deliverability tools

Look for easy setup of SPF, DKIM, and DMARC, plus logs, bounces, and suppression lists.

3) SMTP + API flexibility

SMTP is simple and widely compatible. APIs are often faster, more observable, and include webhooks. The best providers offer both.

4) Approval / compliance

Many services require account approval or domain verification to reduce abuse. That’s a good sign—it protects sender reputation.

5) WordPress compatibility

If you’re using WordPress, ensure the provider works smoothly with SMTP plugins like:
WP Mail SMTP or your preferred mail plugin.

Quick comparison table (limits & best use)

Tip: Always confirm current free-tier limits on the provider’s pricing page—these change over time.

The 10 best free SMTP servers in 2026

1) Brevo (Sendinblue) — free SMTP server (300 emails/day)

Best for: small businesses, WordPress sites, and apps needing simple transactional sending.

Brevo offers a well-known free SMTP relay option with a straightforward daily allowance. It’s a popular choice if you want a reliable sender reputation without managing infrastructure.

• Free plan highlight: up to 300 emails/day
• SMTP setup page: Brevo Free SMTP Server
• Free plan limits (help center): Brevo Free Plan Limits

Pros

• Easy onboarding and beginner-friendly UI
• Good deliverability reputation (when properly authenticated)
• Works well with WordPress SMTP plugins

Cons

• Daily cap can be limiting for bursty apps
• Some features are gated behind paid plans

2) SendPulse SMTP — up to 12,000 emails/month free

Best for: developers and startups that need a higher free monthly volume for transactional messages.

SendPulse’s SMTP service is notable for offering a comparatively high free monthly allowance, which can be useful for new products that can’t justify paid plans yet.

• SMTP pricing: SendPulse SMTP Pricing
• SMTP feature page: SendPulse SMTP Features

Pros

• High free monthly sending compared to many competitors
• SMTP + API options for developers
• Suitable for transactional workflows

Cons

• Always verify the latest limits and conditions
• Account review/verification may apply

3) Mailjet — 6,000 emails/month free (200/day cap)

Best for: small websites, contact forms, basic transactional streams, and early-stage products.

Mailjet is a long-standing email service provider that offers a free plan with a monthly allowance but includes a daily sending maximum—important if you send bursts.

• Pricing page: Mailjet Pricing
• 200/day limit explainer: Mailjet Free Plan Daily Limit
• SMTP relay product page: Mailjet SMTP Relay

Pros

• Reputable provider with mature infrastructure
• Good reporting and tooling on paid tiers
• Great documentation and integrations

Cons

• 200/day cap can be restrictive
• Some advanced features are paid-only

4) SMTP2GO — 1,000 emails/month free (no time limit)

Best for: reliable SMTP relay with a forever-free plan for low-volume senders.

SMTP2GO is widely used as a straightforward SMTP relay. Their free plan is positioned as a no-credit-card entry point for people with small sending needs.

• Pricing page: SMTP2GO Pricing
• Free plan details: SMTP2GO Free Plan

Pros

• No time limit on the free plan
• Simple SMTP integration for most stacks
• Good fit for contact forms and low-volume transactional email

Cons

• 1,000/month is modest for growing apps
• Advanced features may require paid tiers

5) Mailtrap Email API/SMTP — developer-friendly free sending

Best for: developers who want a platform that supports both testing and production sending with clear limits and documentation.

Mailtrap is popular with developers and teams because it combines email testing workflows with sending options. If you’re building a product where email quality matters (templates, testing, deliverability checks), this can be a strong choice.

• Sending limits doc: Mailtrap Free Plan Sending Limits
• SMTP sending tutorial: How to Send Email with SMTP

Pros

• Great documentation for implementation
• Useful for teams (testing + sending workflows)
• Clear visibility into deliverability-related issues

Cons

• Free tier caps (monthly/daily) may be lower than high-volume needs
• Some capabilities are tier-dependent

6) Maileroo — 3,000 emails/month free SMTP

Best for: small businesses and startups that need more than 1,000/month on a free SMTP plan.

Maileroo offers a free SMTP relay tier positioned for low-to-moderate volume sending. If you want a simple “sign up and send” experience without heavy complexity, this is worth considering.

• Pricing page: Maileroo Pricing
• Free SMTP page: Maileroo Free SMTP Server

Pros

• Generous free allowance compared to many SMTP relays
• Good fit for SaaS transactional email at early stage
• Clear upgrade path

Cons

• Always validate deliverability for your specific audience
• Free plan may have throughput constraints

7) AhaSend — 1,000 emails/month free

Best for: transactional emails with a clean, predictable developer-first model.

AhaSend is designed around transparent pricing and a free monthly allowance, making it appealing if you want a simple pay-as-you-go ramp after free usage.

• Pricing page: AhaSend Pricing

Pros

• Simple pricing and onboarding
• Built for transactional use-cases
• Good for small apps and micro-SaaS

Cons

• 1,000/month may be small for fast-growing products
• Brand new domains still need authentication + warm-up

8) MailerSend — 500 emails/month free (daily cap applies)

Best for: very small apps, prototypes, and low-volume transactional streams.

MailerSend offers a small but useful free tier if you want to get started quickly and keep costs at zero while validating your product.

• Pricing page: MailerSend Pricing
• SMTP relay feature: MailerSend SMTP Relay
• Plan limits: MailerSend Plans, Features & Limits

Pros

• Easy entry point for tiny sending volumes
• SMTP relay supported
• Clear documentation

Cons

• 500/month is tight for many production apps
• Approval/domain verification steps may apply

9) Amazon SES — free tier (limited time) + extremely low cost

Best for: technical teams that want to scale and keep email costs very low.

Amazon Simple Email Service (SES) is often chosen for cost efficiency and scalability. It can be “free” only within AWS Free Tier constraints (typically time-limited), but even after that it remains one of the lowest-cost options for high-volume transactional sending.

• Pricing page: Amazon SES Pricing

Pros

• Very scalable, cost-efficient at volume
• Works well for SaaS and platform notifications
• Deep AWS ecosystem integration

Cons

• More complex setup than typical SMTP relays
• May require production access approvals and careful configuration
• “Free tier” is limited (time/volume)

10) Postfix (self-hosted) — free, powerful, and fully controlled

Best for: advanced users who want full ownership of email infrastructure.

Postfix is a widely used open-source mail transfer agent (MTA). The software is free and extremely capable. But hosting your own SMTP server is a deliverability challenge: you must manage DNS, IP reputation, spam controls, and monitoring.

• Official site: Postfix.org
• Ubuntu guide (example): Ubuntu Postfix Documentation
• Anti-spam concept: Spamhaus (blocklist info)

Pros

• Software is free and highly configurable
• Full control over routing, logs, and policies
• Great for custom pipelines and internal systems

Cons

• Hardest option for inbox placement (IP reputation matters)
• Requires ongoing maintenance and security updates
• You must implement compliance, bounce handling, and monitoring

Deliverability checklist (SPF/DKIM/DMARC + best practices)

Getting “sent” is easy. Getting into the inbox is the real work. Use this checklist no matter which SMTP provider you choose:

1) Authenticate your domain

• SPF: Authorizes which servers can send for your domain. Learn: Cloudflare SPF overview
• DKIM: Cryptographically signs outgoing mail. Learn: Cloudflare DKIM overview
• DMARC: Tells receivers what to do if SPF/DKIM fail. Start here: DMARC.org

2) Use a proper “From” identity

Send from addresses like noreply@yourdomain.com or support@yourdomain.com, not free mailbox domains (unless you’re using Gmail/Workspace intentionally).

3) Warm up new domains

Don’t blast large volumes on day one. Start with small sends, gradually ramp, and monitor bounces/complaints.

4) Respect consent & compliance

• For US marketing email rules: CAN-SPAM compliance guide (FTC)
• For EU/UK privacy context: GDPR overview

5) Maintain list hygiene

Remove hard bounces, avoid purchased lists, and keep complaint rates low. Most SMTP providers maintain suppression lists—use them.

6) Add unsubscribe links for marketing mail

Even if you’re using SMTP, include an unsubscribe method for newsletters and promotions. Most email marketing platforms do this automatically; pure SMTP does not.

How to set up SMTP (WordPress + apps)

Step-by-step setup checklist

1. Pick a provider from the list above based on your daily/monthly volume.
2. Add and verify your sending domain inside the provider dashboard.
3. Publish DNS records for SPF/DKIM (and DMARC if possible).
4. Create SMTP credentials (or API key if you’ll use an API).
5. Configure your app or WordPress plugin with host/port/username/password.
6. Send a test email and confirm inbox placement.
7. Monitor bounces and complaints in the provider dashboard.

WordPress recommended approach

Most WordPress sites send email via PHP mail, which can be unreliable on shared hosting. Use SMTP instead:

• Install a plugin like WP Mail SMTP.
• Enter your SMTP provider credentials.
• Send test mail from the plugin settings.
• Check spam placement and adjust authentication if needed.

Developer note: Many providers also offer webhooks for bounces/complaints so you can automatically disable emails to invalid addresses.

FAQs

1) What’s the difference between SMTP and an Email API?

SMTP is the classic protocol and works everywhere. Email APIs often give better logs, webhooks, and performance. Many services provide both; start with SMTP for simplicity.

2) Are free SMTP servers safe?

They can be, if you use reputable providers and set up SPF/DKIM/DMARC. Avoid unknown “free SMTP” sites that don’t clearly explain compliance, abuse prevention, and authentication.

3) Can I use free SMTP for newsletters?

Technically yes, but it’s not recommended. Newsletters should use dedicated email marketing platforms with unsubscribe handling, list management, and compliance tooling.

4) Which is the best free SMTP for WordPress contact forms?

Brevo, Mailjet, and SMTP2GO are common starting points. Choose based on how many form submissions you expect per day and whether you need higher monthly volume.

5) Why do my emails land in spam even with SMTP?

Common reasons: missing SPF/DKIM/DMARC, brand-new domain with no reputation, spammy content, too many links, or sending to unengaged recipients.

6) Do I need a dedicated IP?

Not for most small senders. Dedicated IPs are helpful when you send large volumes and want isolated reputation. Shared IP pools are usually fine for free tiers.

7) What ports should I use for SMTP?

Typical options: 587 (STARTTLS), 465 (implicit TLS), sometimes 25 (often blocked on hosting/VPS). Your provider’s SMTP settings page will tell you what to use.

8) Can I send “cold emails” using free SMTP servers?

You can, but it’s risky: high complaint rates can ruin deliverability and violate provider policies. For outreach, use consent-friendly strategies and comply with laws and provider terms.

9) How do I test if my domain authentication works?

Send a test email to a Gmail address and review headers, or use tools such as MXToolbox to check DNS records.

10) Is self-hosting Postfix “free”?

The software is free, but you still pay for a server/VPS, monitoring, and time. Also, inbox placement is much harder unless you manage IP reputation carefully.

References & further reading

• RFC 5321 (SMTP): rfc-editor.org/rfc/rfc5321
• RFC 7208 (SPF): rfc-editor.org/rfc/rfc7208
• RFC 6376 (DKIM): rfc-editor.org/rfc/rfc6376
• RFC 7489 (DMARC): rfc-editor.org/rfc/rfc7489
• CAN-SPAM (FTC): ftc.gov CAN-SPAM guide
• DMARC basics: dmarc.org

Final note: Free-tier limits change. Before committing, bookmark the pricing page of your chosen provider and review it monthly—especially if your product is growing.