Yes, you can send email through a free SMTP server, with limits. The free options are your mailbox provider's SMTP server (a personal Gmail account allows about 500 emails a day), your web host's mail server, and the free plans of sending services such as Brevo (300 emails a day), Mailjet (6,000 a month, 200 a day), SMTP2GO (1,000 a month, 200 a day), Mailgun (100 a day) and Mailtrap (4,000 a month). Mailpro™ also lets you start free: its 30-day trial includes 500 emails through its SMTP relay, with no credit card. Free plans are fine for testing and low volumes; email that your business depends on, such as order confirmations, invoices or password resets, needs a relay that authenticates your own domain and shows you what was delivered.
Free SMTP servers compared
Free allowances as published on each provider's own pricing or help page, checked in November 2026. Providers change their free plans often, so look at their page before you build on one.
| Option | Free allowance | Good to know |
|---|---|---|
| Mailpro™ (30-day trial) | 500 emails during the 30-day trial | SMTP included, no credit card; sends from your own domain with SPF and DKIM, statistics for every message, servers in Switzerland |
| Gmail (personal account) | About 500 emails a day | Sends from your @gmail.com address; Google may block sending for up to 24 hours when you go over |
| Outlook.com | Not published for free accounts | Microsoft says limits are lower for non-subscribers and for new accounts; Microsoft 365 subscribers get 5,000 recipients a day |
| Brevo | 300 emails a day | Free plan with no time limit, once Brevo approves your account for sending |
| Mailjet | 6,000 emails a month | Maximum 200 emails a day; no credit card |
| SMTP2GO | 1,000 emails a month | Limited to 200 emails a day |
| Mailgun | 100 emails a day | Logs kept for 1 day on the free plan |
| Mailtrap | 4,000 emails a month | No credit card |
| SendGrid | No permanent free plan | Replaced in 2025 by a 60-day trial with 100 emails a day |
Can you use Gmail or Outlook as a free SMTP server?
You can, for personal email and small tests. Mailbox providers set their limits for people, not software: Gmail stops sending after about 500 emails in a day, messages go out from your mailbox address rather than your company domain, and a website or app that logs in with your personal password is a security risk. For anything automated, a relay built for it is the safer choice; see why not to use Outlook or Gmail for email marketing.
What about your web host's SMTP server?
Most hosting plans include a mail server, so it costs nothing extra. The catch is that you share its sending reputation with every other site on the server, and contact-form or WooCommerce emails sent from it often land in spam. If that is happening to you, read why WordPress emails go to spam and how to set up an SMTP server for WordPress.
Can you run your own free SMTP server?
The software is free: Postfix, Exim and hMailServer are open source. Running it well is not. Most internet and cloud providers block outgoing port 25, a new IP address starts with no reputation and lands in spam, and you have to maintain reverse DNS, SPF, DKIM, DMARC, bounce handling and security updates yourself. It suits teams with a system administrator who wants full control; the ports involved are explained in SMTP ports explained.
Not sure what an SMTP server does, or how a relay differs? Start with what an SMTP server is and how it works.
What free SMTP plans usually leave out
- Volume: daily caps of 100 to 300 emails, which a busy shop or a monthly invoice run passes quickly.
- History: short log retention, such as one day on Mailgun's free plan, so you cannot prove an email was delivered last week.
- Reputation: shared IP addresses, so other free users' sending affects yours.
- Time: some "free" offers are trials that end, as SendGrid's did in 2025.
Free SMTP plans vs Mailpro
What you usually get from a free plan, and what you get when you start with Mailpro's free trial:
| Typical free SMTP plan | Mailpro | |
|---|---|---|
| Free sending | 100 to 300 emails a day, for as long as the plan exists | 500 emails during the 30-day trial, then you pay only for what you send |
| Sender address | Often a mailbox address, or one domain | Your own domain, signed with SPF and DKIM |
| Proof of delivery | Short logs, sometimes one day | Statistics for every message: delivered, opened, clicked, bounced |
| Sending reputation | Shared with every other free user | IPs whose reputation Mailpro's team manages |
| Where your data is | Depends on the provider: check before you send personal data | Servers in Switzerland, GDPR compliant |
When should you move from a free SMTP server to a paid one?
- Your website, shop or app sends order confirmations, invoices, bookings or password resets.
- You hit the daily cap, even occasionally.
- Customers say they did not receive an email and you have no way to check.
- You need to send from your own domain with SPF, DKIM and DMARC in place.
- You handle personal data and need to know where your messages are stored.
To compare paid services, see how to choose an SMTP relay service, the best transactional email services and what transactional email costs.
Is Mailpro's SMTP server free?
Yes, to start. The 30-day free trial of the Mailpro SMTP relay service includes 500 emails through SMTP, with no credit card, so you can connect your website or app and check delivery before paying anything. After the trial you pay only for what you send, with a monthly plan or credit packs, not for the number of contacts you store. Messages go through servers hosted in Switzerland, signed with your domain's SPF and DKIM, and every message appears in the SMTP delivery statistics. Prices are on the pricing page.
Frequently asked questions
Is there a completely free SMTP server?
Yes, but every free option has a limit: a daily or monthly cap, a sending address you do not control, or a server you have to run yourself. None of them is meant for high volumes.
Can I try Mailpro's SMTP server for free?
Yes. The 30-day trial includes 500 emails through Mailpro's SMTP relay, with no credit card. Your SMTP username and password are under Settings → SMTP once your account is created.
Is the Gmail SMTP server free?
Yes, with a personal Gmail account, up to about 500 emails a day, sent from your Gmail address.
Which free SMTP server sends the most emails?
On monthly volume, Mailjet's free plan (6,000 emails a month, 200 a day). On daily volume, Brevo (300 a day). Check their pages first: free plans change.
Can I use a free SMTP server for email marketing?
For a few hundred subscribers, a free plan with an email marketing tool can work. A raw SMTP server does not manage unsubscribes, consent or list cleaning for you, so for newsletters use an email marketing platform rather than SMTP alone.
Mailpro SMTP relay
Start free: 500 emails through Mailpro SMTP
Connect your website or app, send from your own domain with TLS, SPF and DKIM, and see what happened to every message. 30-day trial, no credit card, servers in Switzerland.
