BestSends Guide · Tested by Carlos Gil
7 Best Free SMTP Servers in 2026
A free SMTP relay is the cheapest way to send transactional and marketing email from your app or site. Here are the ones worth wiring up, with the send limits I verified myself.
Every free SMTP plan trades something away. Some cap you at a few hundred sends a day, some throttle by month, some require a credit card, and some quietly route you through shared IPs with a mixed reputation. I connected each of these relays to a real domain with SPF, DKIM, and DMARC in place and watched what landed. Below is what each free tier actually gives you, and where it breaks.
At a glance
| Tool | Best for | From | Free plan | Rating | Try |
|---|---|---|---|---|---|
| BrevoTop pick | Apps and sites that need a dependable free relay | $9/mo paid | 300 emails/day forever | 4.7 | Visit → |
| Amazon SES | Engineering teams sending high volume | $0.10 per 1,000 | 3,000 message charges/mo for 12 months | 4.5 | Visit → |
| MailerLite | Marketers who want a relay plus a builder | $10/mo | 1,000 subscribers, 12,000 emails/mo | 4.5 | Visit → |
| Sender | Ecommerce senders on a zero budget | $8/mo | 2,500 subscribers, 15,000 emails/mo | 4.2 | Visit → |
| Moosend | Testing a full featured relay before paying | $9/mo | 30-day trial, unlimited sends | 4.1 | Visit → |
| Mailchimp | Teams already inside Mailchimp | $13/mo | 500 contacts, 1,000 emails/mo | 3.9 | Visit → |
| Omnisend | Shopify and WooCommerce stores | $16/mo | 250 contacts, 500 emails/mo | 4.4 | Visit → |
What we love · what we don't
What we love
- Brevo and Sender both offer genuinely permanent free tiers
- Amazon SES makes volume sending almost free
- Every option on this list supports SPF, DKIM, and DMARC properly
What we don't
- Free tiers usually mean shared IPs you do not control
- Daily caps break large one off sends
- Branding footers appear on most free plans
The ranking
1. Brevo
Brevo hands you SMTP credentials the moment you verify a sender, and the free tier is not a trial. You get 300 emails a day indefinitely, which covers password resets, receipts, and a small newsletter without paying anything.
What sets it apart is the tooling around the relay. You get delivery logs, bounce and complaint tracking, and DKIM setup instructions that actually match what mailbox providers expect in 2026.
The ceiling is the daily cap rather than a monthly one, so a single large send can hit the wall. If your traffic is spiky, plan around that or move to a paid tier.
Pros
- 300 sends a day forever
- No credit card required
- Delivery logs on free tier
- Clean SPF and DKIM setup
Cons
- Daily cap, not monthly
- Brevo footer on free sends
Who it's for
Developers and small businesses that want a free relay they can leave in production.
Skip it if
You send in large bursts rather than a steady trickle.
2. Amazon SES
SES is a raw relay. There is no campaign builder, no templates worth using, and no hand holding. What you get is the lowest cost per thousand in the market and deliverability that holds up when you configure it properly.
The free allowance covers 3,000 message charges a month for your first year. After that you pay pennies, which is why almost every product team at scale ends up here.
You start in sandbox mode and have to request production access, and you own your reputation entirely. Set up a dedicated configuration set, monitor bounce and complaint rates, and do not treat it as a marketing platform.
Pros
- Lowest cost per email anywhere
- Scales without limits
- Solid infrastructure and uptime
Cons
- Sandbox approval required
- No marketing features
- You manage reputation yourself
Who it's for
Teams with an engineer who can own deliverability.
Skip it if
You want a UI to build and schedule campaigns.
3. MailerLite
MailerLite is a marketing platform first, but the free plan gives you a monthly allowance generous enough to double as a light transactional relay when paired with its sending API.
The editor is the cleanest I have used, landing pages are included, and automation is available on free with a single workflow.
Approval is manual. MailerLite reviews new accounts, so plan for a short wait before your first send goes out.
Pros
- 12,000 free emails a month
- Best in class editor
- Landing pages included free
Cons
- Manual account approval
- Lighter automation on free
Who it's for
Small businesses and freelancers doing marketing and light transactional sends.
Skip it if
You need pure high volume SMTP with no marketing layer.
4. Sender
Sender is the volume play on free. Fifteen thousand emails a month is more than most small stores use, and automation is included rather than paywalled.
Deliverability was respectable in my tests, though the shared sending pools are less predictable than Brevo or SES.
The product feels less polished and support is slower, which is the tradeoff for the allowance.
Pros
- 15,000 free emails a month
- Automation on the free plan
- Ecommerce blocks built in
Cons
- Shared IP pools vary
- Dated interface
- Slower support
Who it's for
Stores and side projects that need volume without cost.
Skip it if
Inbox placement is business critical.
5. Moosend
Moosend no longer has a forever free plan, but the 30 day trial is unrestricted, which makes it the best way to stress test a relay against your own volume.
Automation and segmentation are genuinely strong for the price once you convert.
After the trial you pay, so this is not a long term free option.
Pros
- Unlimited sends in trial
- Strong automation
- Transactional API included
Cons
- No forever free tier
- Trial only 30 days
Who it's for
Anyone evaluating relays before committing.
Skip it if
You need free permanently.
6. Mailchimp
Mailchimp still has a free plan, and it is the weakest of the group at 1,000 emails a month across 500 contacts.
True SMTP relay sending runs through the Transactional add on, which is not free. The free tier is marketing only.
Included here because so many teams start here, not because it is the right relay.
Pros
- Familiar interface
- Huge integration library
Cons
- Only 1,000 free emails a month
- Transactional costs extra
- Priciest as you grow
Who it's for
Teams already standardized on Mailchimp.
Skip it if
You are choosing fresh today.
7. Omnisend
Omnisend gives you the full automation suite on free, which no other tier here does. The catch is a 500 email monthly ceiling.
Abandoned cart, browse abandonment, and post purchase flows all work on the free plan, which makes it useful for a store with a small list.
As a general purpose SMTP relay it is the wrong tool. Use it as a store platform, not a transactional pipe.
Pros
- Full automation on free
- Native store integrations
- SMS in the same flows
Cons
- Only 500 free emails a month
- Not a general purpose relay
Who it's for
Small stores testing ecommerce automation.
Skip it if
You need app transactional email.
How we chose these platforms
Best email tool by use case
How I tested these tools
Testing period: June to July 2026
What I tested
- Brevo
- Amazon SES
- MailerLite
- Sender
- Moosend
- Mailchimp
- Omnisend
What I did not test
- Self hosted Postfix
- Gmail SMTP relay
Full methodology: /how-we-test
The full comparison table — all 7 platforms
Every platform tested, at a glance. Sort by rating in your head; the ranking above tells you our verdict.
| Tool | Starting price | Free plan | Automation | Best for | Rating | Try |
|---|---|---|---|---|---|---|
| Brevo | Free | 300/day forever | Solid | Best free relay overall | 4.7 | Try free → |
| Amazon SES | $0.10/1k | 3,000/mo for 12 months | None | High volume sending | 4.5 | Try free → |
| MailerLite | Free | 12,000/mo | Solid | Marketers | 4.5 | Try free → |
| Sender | Free | 15,000/mo | Light | Largest free allowance | 4.2 | Try free → |
| Moosend | Trial | 30 days unlimited | Deep | Full featured trial | 4.1 | Try free → |
| Mailchimp | Free | 1,000/mo | Solid | Existing Mailchimp teams | 3.9 | Try free → |
| Omnisend | Free | 500/mo | Deep | Small stores | 4.4 | Try free → |
Which email tool should you use?
Skip the ranking. Pick the sentence that describes you.
Pricing at every list size
Estimated monthly cost on each platform's standard plan, billed monthly. Cheapest at each tier highlighted.
| Tool | 1,000 | 10,000 | 50,000 | 100,000 |
|---|---|---|---|---|
| Brevo | Free | $9/mo | $29/mo | $65/mo |
| Amazon SES | Free tier | $1/mo | $5/mo | $10/mo |
| MailerLite | Free | $10/mo | $39/mo | $73/mo |
| Sender | Free | $8/mo | $29/mo | $55/mo |
| Moosend | Trial | $9/mo | $48/mo | $88/mo |
Frequently asked questions
It is a mail relay you connect to with a hostname, port, username, and password so your app or site can send email without running your own mail server. Free plans cap how many messages you can push through per day or month.
Update history (1)
- Jul 31, 2026First publication with verified free send limits for all seven relays.
Keep reading
Our top pick
Brevo leads our testing
Tested hands on against every platform in this guide, on real accounts and real campaigns.
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About the Author
Carlos Gil is the Editor in Chief of BestSends and the author of The End of Marketing. He has spent 15+ years in email marketing with in-house roles at LinkedIn, GetResponse, BMC Software, Winn-Dixie, and Save-A-Lot.
Read more about Carlos