A free SMTP server is fine for website contact forms, small apps, printers and test projects, as long as the free allowance covers your volume and you set up authentication on your domain. Hosted SMTP relays are easiest, while open source mail servers give full control. This page lists ten free options in no particular order, then shows how to choose.
SMTP is the plain, old protocol that still moves most email, and it's what your website, CRM plugin or office scanner uses to send messages. The question is which server it sends through, because that decides whether your email lands in the inbox or disappears.
Below are ten free options in no particular order, sorted alphabetically, from hosted SMTP relays with free tiers to open source servers you run yourself. Each description comes from the service's own website, re-checked today. If you're learning email from the ground up, my guide on where to learn email marketing from scratch is a good companion.
For most small businesses, a hosted relay is the sensible choice. Running your own mail server is a serious job, and it's only worth it if you want full control and you're happy to look after deliverability yourself.
Free SMTP services at a glance
In the free plan column, Yes means the service's own site describes a free plan, free tier or free open source download. Monthly and daily limits vary a lot, so check them against your volume.
| Tool | Type | Good for | Free plan |
|---|---|---|---|
| Brevo | Email platform with SMTP | Free daily SMTP sending | Yes |
| Elastic Email | Sending API and campaigns | Free sending plus campaigns | Yes |
| Mailcow | Open source mail server suite | Self-hosted mail with a web UI | Yes |
| Maileroo | Email API and SMTP | Simple SMTP for small apps | Yes |
| MailerSend | Transactional email service | App email with templates | Yes |
| Mailjet | Email API and newsletters | SMTP plus a newsletter editor | Yes |
| Postal | Open source mail delivery platform | Running your own sending servers | Yes |
| Resend | Email API for developers | Modern web app stacks | Yes |
| SMTP2GO | SMTP relay and API | Websites, apps and office devices | Yes |
| Sweego | European email API | EU-based SMTP and SMS | Yes |
Ten free SMTP services and servers
Brevo
Best for: Small businesses that want free SMTP sending alongside newsletters and a simple CRM.
Elastic Email
Best for: Businesses that want SMTP relay and campaign tools from one account with a free plan.
Mailcow
Best for: Technical teams who want a self-hosted mail server suite in Docker with a web interface.
Maileroo
Best for: Small apps and websites that want an easy SMTP relay with a free tier.
MailerSend
Best for: Product teams who want SMTP and API sending with templates on a free plan.
Mailjet
Best for: Teams that want SMTP relay alongside a drag-and-drop newsletter editor on a free plan.
Postal
Best for: Developers who want an open source mail delivery platform to run on their own servers.
Resend
Best for: Developers who want a free tier for sending from modern web apps through SMTP or an API.
SMTP2GO
Best for: Businesses that need SMTP relay for websites, apps and devices like printers and scanners.
Sweego
Best for: European businesses that want local SMTP and API sending with a free tier.
Why your Gmail account isn't an SMTP server
Lots of people point their website at their own Gmail login and wonder why it stops working. Google's Workspace help lists a daily sending limit of 2,000 messages per user account, 1,500 for mail merge and 500 for trial accounts, and personal Gmail accounts hit a limit after sending to more than 500 recipients in a day.
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Once you hit a limit, sending stops for up to 24 hours. A dedicated SMTP relay is built for automated email, keeps your personal mailbox out of the picture and gives you logs when something goes wrong.
How to choose a free SMTP service
- Free allowance: check the daily and monthly limits against your real volume.
- Authentication: make sure you can add SPF and DKIM for your domain.
- Ports: confirm the ports it offers work on your web host, as some hosts block port 25.
- Logs: you'll want to see what was sent and what bounced.
- Data location: pick a provider whose storage fits your privacy obligations.
Connecting a website to an SMTP relay
- Create an account and verify your sending domain.
- Add the SPF and DKIM records to your DNS.
- Install an SMTP plugin or add the settings to your app.
- Send a test message to a few different inbox providers.
- Check the relay's logs to confirm delivery.
SMTP setup mistakes to avoid
- Sending from the web server. Unauthenticated email often lands in spam.
- Using a personal password. Use the relay's own credentials or app passwords.
- Skipping DKIM. SPF alone isn't enough for many providers.
- Never checking logs. Look weekly, even when nothing seems wrong.
If you're choosing a full email platform rather than just SMTP, my list of email marketing software for small business covers the options.
What to do when emails stop arriving
Start with the relay's logs. If the message shows as delivered, the problem is usually spam filtering at the other end, so check your SPF, DKIM and DMARC results. If it shows as rejected, the log will normally say why, such as an unverified sender or a hit limit. If it never appears at all, the problem is the connection between your site and the relay, so check the port, username and password.
Do you make SMTP sending? Tool makers can ask to be considered for a featured place on this list.
My plain advice on free SMTP
For a contact form or a small shop, a hosted relay's free tier is all you need, and it'll be far more reliable than sending from your hosting server or personal inbox.
Run your own mail server only if you enjoy that kind of work. Self-hosting gives you control, but you'll be the one fixing delivery when a mailbox provider stops trusting your server.
Frequently asked questions
What is a free SMTP server?
It's a service or piece of software that sends email for your website or app at no charge, usually up to a daily or monthly limit.
Can I use Gmail as an SMTP server?
You can for small volumes, but Google sets daily sending limits, and sending stops for up to 24 hours once you hit them.
What are Google Workspace's sending limits?
Google's help lists 2,000 messages per user per day, 1,500 for mail merge and 500 for trial accounts.
Which SMTP port should I use?
Most relays recommend port 587 or 465 with encryption. Many hosts block port 25.
Do I need SPF and DKIM for SMTP?
Yes. They prove you're allowed to send for your domain and help keep email out of spam.
Is self-hosting a mail server a good idea?
Only if you're comfortable managing servers and reputation. Hosted relays are simpler for most businesses.
Why do my website emails go to spam?
Often because they're sent from the web server without authentication. A relay with SPF and DKIM usually fixes it.
Can I send newsletters through free SMTP?
Check the provider's terms. Some free tiers are meant for transactional email only.
