Free SMTP Server: Best Free SMTP Services & Relay Setup Guide (2026)
Find the best free SMTP servers and relay services. Compare free SMTP options, setup guides, and learn how to send email reliably without paying.
An SMTP server is what actually delivers your email. Whether you send transactional messages, newsletters, or campaigns, a managed SMTP relay is what gets those messages into the inbox instead of spam. Here is how to do it for free, with no server to run.
What Is an SMTP Server?
SMTP (Simple Mail Transfer Protocol) is how email moves across the internet. An SMTP server accepts your message and hands it to the recipient’s mail server. The hard part is not the protocol; it is the sender reputation and authentication that decide whether the message lands in the inbox.
Self-Hosted vs Managed SMTP
| Aspect | Self-hosted | Managed service |
|---|---|---|
| Cost | Server + your time | Free tiers available |
| Setup | Complex (Postfix, etc.) | API key or SMTP credentials |
| Deliverability | You own reputation | Provider manages it |
| Authentication | Manual SPF/DKIM/DMARC | Auto-configured |
| Monitoring | DIY | Dashboard included |
| Maintenance | Ongoing | None |
Recommendation: use a managed relay. A self-hosted server is rarely “free” once you count IP warm-up, blacklist firefighting, and lost deliverability.
Best Free SMTP Servers
1. Brevo SMTP, Best All-Round Free Relay
| Feature | Detail |
|---|---|
| Free limit | 300 emails/day (~9,000/month) |
| Authentication | SPF + DKIM included |
| API | REST + SMTP relay |
| Tracking | Opens, clicks, bounces |
| Reputation | Managed by Brevo |
| Extras | Free CRM, marketing, and SMS on the same account |
Setup: create a free account, get SMTP credentials, point your app at:
- Host:
smtp-relay.brevo.com - Port: 587 (TLS)
- Auth: your Brevo SMTP key
The advantage over a pure relay is that the same free account also gives you a CRM and marketing tools, so transactional and marketing email can share one verified domain and reputation. For Shopify, Tajo syncs store data into that account so order and shipping emails carry real customer context. Get free Brevo SMTP.
2. SMTP2GO, Top-Rated Free Relay
| Feature | Detail |
|---|---|
| Free limit | 1,000 emails/month |
| Authentication | SPF + DKIM + DMARC |
| API | REST + SMTP |
| Tracking | Detailed reporting and alerts |
Consistently rated a leading free SMTP relay for deliverability. Best for teams that want a focused, reliable relay with strong reporting.
3. SendGrid, Developer-Friendly
| Feature | Detail |
|---|---|
| Free limit | 100/day |
| Authentication | SPF + DKIM |
| API | REST + SMTP |
| Tracking | Opens, clicks |
Solid SDKs and documentation. The 100/day free cap is tight for anything beyond small apps.
4. Amazon SES, Cheapest at Scale (AWS)
| Feature | Detail |
|---|---|
| Free limit | New accounts: ~3,000 message charges/month (12-month free tier) |
| Authentication | Full setup required |
| API | AWS SDK / SMTP |
| Tracking | Via SNS / event destinations |
The old “62,000 free from EC2” model has been replaced; new customers now get roughly 3,000 free message charges per month for the first year. Still the cheapest option at high volume, but it expects AWS familiarity and you manage more of the deliverability setup yourself.
5. Gmail SMTP, Personal Use Only
| Feature | Detail |
|---|---|
| Free limit | ~500/day |
| Authentication | OAuth2 |
| Suitable for | Personal scripts only |
| Not for | Marketing or bulk email |
Fine for a hobby script. Using it for bulk or marketing email risks your account and domain reputation.
SMTP Relay Setup Guide
WordPress
Install the Brevo plugin or WP Mail SMTP, choose the mailer, enter SMTP credentials, send a test, done.
Web applications
SMTP_HOST=smtp-relay.brevo.comSMTP_PORT=587SMTP_USER=your-loginSMTP_PASS=your-smtp-keySMTP_TLS=trueTransactional email
For order confirmations, password resets, account notifications, and shipping updates, prefer the API over plain SMTP for faster, more reliable delivery. See our transactional email guide and free transactional email guide.
Deliverability Tips
- Authenticate your domain: SPF, DKIM, DMARC
- Warm up gradually: do not send 10K on day one
- Monitor bounces: remove invalid addresses (bounce guide)
- Check blacklists weekly: (blacklist guide)
- Use a consistent From address: reputation builds on the sender, not the message
When to Upgrade
Free SMTP covers small sites under 300 emails/day, transactional email for small apps, and testing. Upgrade when you need higher limits, a dedicated IP, advanced analytics, priority support, or an SLA. Brevo’s paid SMTP starts around $9/month for 5,000 emails.
FAQ
Is a free SMTP relay reliable enough for production transactional email? Yes, for low volume. Free tiers from Brevo, SMTP2GO, and SendGrid run on the same managed infrastructure as their paid plans; you just hit a daily or monthly cap.
Should transactional and marketing email use the same SMTP setup? They can share a domain but should ideally use separate streams or subdomains so a marketing reputation issue never blocks password resets. Brevo supports both on one account.
Why not just self-host with Postfix to avoid limits? Because new IPs start with zero reputation and most inbox providers throttle or junk them by default. The time spent warming and defending an IP usually costs more than a paid plan.
Does Tajo send the email itself? No. Tajo syncs Shopify data into Brevo; Brevo’s SMTP and API do the sending. The benefit is that order and customer context is already attached to the contact.