Free SMTP server

Send marketing and transactional emails that actually reach inboxes

Mailjet’s free SMTP server sends both marketing and transactional emails reliably. One powerful platform for developers and marketers with GDPR compliance, 99.9% uptime, unlimited contacts, and setup in minutes.

  • Trusted by 100K+ companies

  • 48B emails sent annually

  • GDPR & ISO certified

Example of transactional email messages with API code snippet in Mailjet, showing welcome, password reset, and ride receipt emails.
Mailjet security and compliance with ISO 27001 certification, GDPR compliance, CSA certification, and European data hosting.

Why growing teams choose Mailjet’s free SMTP server

All-in-one email platform

Manage marketing and transactional messages in one place, giving every team clear visibility and saving hours each week.

Predictable email pricing

Send to unlimited contacts with volume-based pricing, so budgets stay on track even as your list grows from thousands to millions.

Proven scale and reliability

Rely on 99.9% uptime and 48B emails sent yearly by 100K+ companies to keep every important message flowing smoothly.

Built-in compliance

Meet GDPR and ISO requirements automatically with EU-based infrastructure and certified data handling.

Inbox being filtered by SPF, DKIM, and DMARC.

A single platform for all your email sending

Mailjet combines marketing campaigns and transactional emails in one platform, eliminating the need for multiple tools. With a free SMTP server and robust email API, both developers and marketers can send emails confidently with built-in GDPR compliance, 99.9% uptime, and unlimited contacts.

  • Unified platform for all email needs

  • Developer-friendly SMTP relay and REST API

  • Intuitive no-code editor for marketers

  • Transparent, volume-based pricing

Deliverability statistics for a Mailjet email campaign.

Use the MTA and framework you prefer

Use your preferred Message Deliverability Agent or Message Transfer Agent (MTA) such as Postfix, Exim, or Exchange to send via Mailjet’s SMTP relay. You can also use PHP, Java, or any other frameworks or languages you prefer, making it easier for you to start sending immediately.
Where you land in the inbox.

Improve your inbox placement

With our SMTP relay, you will not only increase your chance of landing in the inbox, but your emails will get there faster. Easily set up SPF, DMARC, and DKIM records to authenticate your domain and start sending. Our deliverability support team will be there every step of the way to help get you set up, monitor, and maintain high deliverability rates.
Email API configuration

CONSOLIDATE TOOLS

Eliminate fragmented email tools and simplify every workflow

Mailjet unifies marketing and transactional emails with contact lists, templates, analytics, and APIs so developers and marketers collaborate smoothly without costly integrations.

  • One login for every email need

  • Unified analytics and contact lists

  • No more fragile integrations

Statistics from Mailjet that allow for continuous improvement.

PREDICTABLE COSTS

Pricing that scales with you, not your contact list

Mailjet’s volume-based plans include unlimited contacts, giving finance teams predictable invoices while marketing enjoys the freedom to grow lists without penalty.

  • Unlimited contacts included

  • Volume-based plans scale smoothly

  • Transparent monthly billing

POPULAR USE CASES

Fits every growing business model

E-commerce and retail

Send order confirmations, shipping updates, abandoned cart reminders, and promotions from a single platform that unifies marketing and transactional flows.

SaaS and technology

Deliver password resets, account alerts, onboarding sequences, and product news with guaranteed reliability and rich analytics.

Digital services

Automate appointment reminders, service confirmations, customer messaging, and newsletters without juggling multiple tools or vendors.

Startups and SMBs

Scale from first customer to millions of sends with unlimited contacts, predictable costs, and no need to switch providers.

POWERFUL FEATURES

Everything you need to send and track email

Transactional Email API

Automatically deliver time-sensitive messages like password resets and receipts with guaranteed speed and reliability.

Marketing email campaigns

Design, segment, and send engaging campaigns to large lists using intuitive templates and advanced targeting.

SMTP relay and REST API

Integrate in minutes using familiar SMTP credentials or powerful REST endpoints. Your choice, same great results.

Deliverability monitoring

Track opens, clicks, bounces, and blocks in real time to safeguard sender reputation and improve inbox placement.

Server-side personalization

Insert dynamic, recipient-specific content that boosts engagement and drives higher conversion rates.

Flexible port options

Connect via ports 25, 465, 587, or 2525 with TLS or SSL encryption for secure, reliable delivery in any environment.

Real-time analytics

Access detailed performance dashboards to make data-driven decisions and continuously improve results.

GDPR compliance built-in

Meet European data privacy requirements automatically with ISO-certified, EU-based infrastructure.

Where you land in the inbox.

Simple, transparent pricing with unlimited contacts included

Mailjet offers volume-based pricing with unlimited contacts, so you never pay more as your list grows. Start with a free SMTP server and upgrade as your needs evolve.

  • Free tier available

  • No setup fees

  • Cancel anytime

SMTP configuration.

Start sending with Mailjet’s free SMTP server today

Experience reliable email delivery, unlimited contacts, and built-in GDPR compliance all in one platform. Join 100K+ companies who trust Mailjet for their marketing and transactional email needs.

Free SMTP service FAQs

A free SMTP server allows you to send emails from your applications without upfront cost. You receive SMTP credentials to relay messages through secure, professional infrastructure with built-in deliverability features.

Limits depend on the provider. With Mailjet, you can start sending immediately and scale from 6,000 to over 500,000 emails monthly with volume-based pricing.

Yes. Mailjet is GDPR compliant, ISO27001 and ISO27701 certified, SOC 2 compliant, and hosted in EU-based data centers for data protection.

Yes. Mailjet’s SMTP relay supports both marketing and transactional messages. You can send newsletters, promotions, product announcements, and other bulk campaigns through SMTP, and you can also deliver account notifications, password resets, receipts, and other time sensitive messages through the same channel. Most customers segment the two by applying different sending addresses, sub accounts, or custom message headers so engagement data stays separate and deliverability can be monitored accurately.

Integration is fast and simple. Mailjet provides clear documentation, straightforward SMTP setup, and developer-friendly tools so most teams connect in minutes.