Free Email APIs and SMTP Services
Which transactional email APIs and SMTP services let you send for free today, how many emails a day and a month, on how many domains and with whose branding, read from the providers' own pages.
Free allowances read on each provider's own pages, all checked on or after . Free plans and their sending limits change often, and several providers have turned free plans into trials: confirm them on the provider's page before you build on them.
Email APIs you can send from for free today include Resend (3,000 emails a month, up to 100 a day), Amazon SES (up to $200 in AWS Free Tier credits), Mailtrap (4,000 emails a month), Zoho CPaaS (ZeptoMail) (first credit free: 10,000 emails), and SMTP2GO (1,000 emails a month, up to 200 a day). Each of the 16 allowances below links to the provider's page that states it, with its daily and monthly limits, sending domains and whether it adds its own branding.
Transactional email APIs send the emails an app sends on its own: sign-up confirmations, password resets, receipts and alerts, through an HTTP API or an SMTP relay. Most providers let a developer start free, with a plan that renews every day or month or with free credits or a trial.
The monthly headline is rarely the limit that bites. A free plan can cap sending per day as well as per month, allow one sending domain, add the provider's logo to every email, keep logs for a day, or hold a new account in a sandbox or a review until it may send to anyone. Each provider below shows its sending limits, domains and branding, whether a card is needed and what comes after the free allowance, quoted from the provider's own page with the date we read it.
Which providers we picked and the order they appear in are our editorial choices; the terms are the providers'. Some of these providers pay us a referral commission when someone signs up through our link: those links are labeled, and they play no part in which providers are listed or where.
Free plans that keep sending
No end date: the provider lets you send this many emails for free every day or month, within the stated limits.
- 1
Resend
A developer-first API with no approval wait
Resend's free plan sends 3,000 emails a month, up to 100 a day, from up to 3 verified domains, and every account has production access from signup with no approval. Received emails count toward the quota.
- Domains and branding
- Up to 3 verified domains (source: resend.com)
- After the free allowance
- Pro: $20 a month for 50,000 emails (source: resend.com)
Start free at ResendTerms read on resend.com on Resend: the free allowance and how to start Resend for Y Combinator startups: what startups get - 2
Mailtrap
More free monthly sends from one domain
Mailtrap's free sending plan gives 4,000 emails a month, capped at 150 a day, from 1 verified domain with no card. New domains get a compliance check before you can send.
- Sending limits
- 150 a day; 3-day logs; 1 user (source: docs.mailtrap.io)
- Domains and branding
- 1 sending domain (source: docs.mailtrap.io)
- Payment card
- No card needed (source: mailtrap.io)
- After the free allowance
- Basic: $15 a month for 10,000 emails (source: docs.mailtrap.io)
Start free at MailtrapTerms read on docs.mailtrap.io on Mailtrap: the free allowance and how to start - 3
SMTP2GO
An SMTP relay for several domains
SMTP2GO's free plan gives 1,000 emails a month, up to 200 a day, from up to 5 sender domains, with no card. An hourly limit of 25 applies until you verify a sender domain, and sign-up needs an address on your own domain.
- Domains and branding
- Up to 5 sender domains or addresses (source: support.smtp2go.com)
- Payment card
- No card needed (source: smtp2go.com)
- After the free allowance
- Paid plans from $15 a month (source: smtp2go.com)
Start free at SMTP2GOReferral linkTerms read on smtp2go.com on SMTP2GO: the free allowance and how to start - 4
Brevo
The most free sends a day, with Brevo's sticker
Brevo's free plan sends up to 300 emails a day, about 9,000 a month, by API and SMTP as well as campaigns, with no card. Brevo approves the account before it can send, and free emails carry the Sent by Brevo sticker.
- What's free
- 300 emails a day (source: brevo.com)
- Domains and branding
- Brevo sticker on emails; removing it is paid (source: brevo.com)
- Payment card
- No card needed (source: brevo.com)
- After the free allowance
- Starter: $9 a month, from 5,000 emails (source: brevo.com)
Start free at BrevoTerms read on brevo.com on Brevo: the free allowance and how to start Brevo Startups & VCs Program: what startups get - 5
Mailjet
A large monthly allowance, with Mailjet's logo
Mailjet's free plan sends up to 6,000 emails a month with a maximum of 200 a day, by API, SMTP relay and webhooks, and needs no card at sign-up. Free emails keep the Mailjet logo, which is removed from the Essential plan up.
- What's free
- 6,000 emails a month (source: mailjet.com)
- Sending limits
- 200 emails a day (source: mailjet.com)
- Domains and branding
- Mailjet logo stays on free emails (source: mailjet.com)
- Payment card
- No card needed at sign-up (source: mailjet.com)
- After the free allowance
- Starter: $9 a month for 8,000 emails (source: mailjet.com)
- 6
Elastic Email
A permanent free plan to anyone
Elastic Email's Email API free plan covers up to 3,000 emails a month, at most 100 a day, and is permanently free with no card. The account is verified before it can send.
- Sending limits
- 100 emails a day (source: help.elasticemail.com)
- Domains and branding
- Sends from your own domain (SPF, DKIM) (source: elasticemail.com)
- Payment card
- No card needed (source: elasticemail.com)
- After the free allowance
- From $19 a month for up to 50,000 emails (source: elasticemail.com)
Start free at Elastic EmailTerms read on elasticemail.com on Elastic Email: the free allowance and how to start - 7
AhaSend
A small, simple transactional API
AhaSend's free plan gives 1,000 emails a month from up to 3 sending domains, with no card and no trial period. Hourly sending limits start low on new accounts and grow with reputation.
- What's free
- 1,000 emails a month (source: ahasend.com)
- Domains and branding
- 3 sending domains (source: ahasend.com)
- Payment card
- No card needed (source: ahasend.com)
- After the free allowance
- Pro: $10 a month for 25,000 emails (source: ahasend.com)
- 8
Plunk
Open source, free to self-host
Plunk's free plan gives 1,000 emails a month with custom domains and no card, and lists Plunk branding on emails; inbound emails count toward the allowance. Plunk is open source and can be self-hosted for free.
- What's free
- 1,000 emails a month (source: useplunk.com)
- Domains and branding
- Custom domains; Plunk branding on emails (source: useplunk.com)
- Payment card
- No card needed (source: useplunk.com)
- After the free allowance
- $0.001 per email, no base fee (source: useplunk.com)
- 9
Bird Email (SparkPost)
SparkPost's infrastructure, now under Bird
SparkPost is now Bird Email, whose free plan sends 1,000 emails a month, capped at 50 a day, from 1 sending domain, with no card. Sends past either cap are rejected rather than billed.
- Domains and branding
- 1 sending domain (source: bird.com)
- Payment card
- No card needed (source: bird.com)
- After the free allowance
- $15 monthly deposit, $0.40 per 1,000 emails (source: bird.com)
Start free at BirdTerms read on bird.com on Bird Email (SparkPost): the free allowance and how to start - 10
Postmark
Testing a deliverability-first service
Postmark's Developer plan gives 100 emails every month and never expires, with up to 10 sending domains and no card. Until Postmark approves the account, you can send only to your own verified domains.
- Sending limits
- No overages on the free plan (source: postmarkapp.com)
- Domains and branding
- Up to 10 custom sending domains (source: postmarkapp.com)
- Payment card
- No card needed (source: postmarkapp.com)
- After the free allowance
- Basic: $15 a month (source: postmarkapp.com)
Start free at PostmarkReferral linkTerms read on postmarkapp.com on Postmark: the free allowance and how to start Postmark Bootstrapper Credit: what startups get - 11
Mailgun
Testing the API before you add a card
Mailgun's free plan sends 100 emails a day, with 1 day of logs. Without a card on file, or from the sandbox domain, you can send only to up to 5 authorized recipients.
- What's free
- 100 emails a day (source: mailgun.com)
- Domains and branding
- 1 custom sending domain (pricing page) (source: mailgun.com)
- After the free allowance
- Basic: from $15 a month for 10,000 emails (source: mailgun.com)
- 12
MailerSend
A free plan after a short approval
After its sandbox and an account approval, MailerSend's free plan sends 500 emails a month, up to 100 a day, from 1 domain. It asks for card details to prevent abuse and does not charge the card.
- Domains and branding
- 1 domain, 1 template, 1 API token (source: mailersend.com)
- After the free allowance
- Hobby: $75.60 a year for 5,000 a month (source: mailersend.com)
Start free at MailerSendTerms read on mailersend.com on MailerSend: the free allowance and how to start - 13
Scaleway Transactional Email
EU-hosted transactional email
Scaleway's Transactional Email includes 300 free emails a month in its pay-as-you-go plan, from up to 5 domains, then 0.25 euros per 1,000. It is transactional only, and a Scaleway account needs a valid card.
- What's free
- 300 emails a month (source: scaleway.com)
- Domains and branding
- 5 domains (source: scaleway.com)
- After the free allowance
- Pay as you go: 0.25 euros per 1,000 emails (source: scaleway.com)
Free credits or a trial to start with
A free amount of sending once, or for a set time; after it, sending is paid.
- 1
Amazon SES
The cheapest sending at volume
New AWS customers get up to $200 in Free Tier credits that can pay for Amazon SES. New SES accounts start on the Essentials plan at $0.16 per 1,000 emails ($0.10 a la carte), and in a sandbox of 200 messages a day to verified addresses until AWS grants production access.
- Domains and branding
- Up to 10,000 addresses and domains per Region (source: aws.amazon.com)
- After the free allowance
- New accounts start on Essentials: $0.16 per 1,000 (source: aws.amazon.com)
Start free at Amazon Web ServicesTerms read on aws.amazon.com on Amazon SES: the free allowance and how to start AWS Activate Founders: what startups get - 2
Zoho CPaaS (ZeptoMail)
A one-time 10,000 emails, transactional only
Zoho's transactional email service, renamed from ZeptoMail to Zoho CPaaS, gives the first credit of 10,000 emails free, valid for 6 months. It is for transactional email only, with a 100-a-day cap until Zoho validates the account.
- After the free allowance
- US$2.50 per 10,000 emails (source: zoho.com)
Start free at ZohoTerms read on zoho.com on Zoho CPaaS (ZeptoMail): the free allowance and how to start - 3
SendGrid
Trying SendGrid: its free plan is now a trial
Twilio SendGrid no longer has a free plan for new accounts: a 60-day trial sends 100 emails a day with no card, and sending stops when it ends unless you upgrade. Trial accounts may be reviewed before they are active.
- Domains and branding
- Authenticate your domain; count not stated (source: support.sendgrid.com)
- Payment card
- No card needed (source: twilio.com)
- After the free allowance
- Essentials from $19.95 a month (source: twilio.com)
Startup programs that pay for email sending
Programs from these providers, and cloud credits that cover their sending, largest tracked value first. Most ask for an application, and several for funding limits or a backing investor.
- Catalog valueSource and terms for Postmark Bootstrapper CreditApply to Postmark Bootstrapper CreditReferral link
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How this comparison is built
The list covers email APIs and SMTP services a developer can send from for free today without applying to a program, grouped into free plans that renew every day or month and free credits or trials. The order and the "best for" notes are our editorial reading of each provider's terms. Every term comes from the provider's own pricing, documentation or terms page on the date shown, never from a third-party list; follow each link for the full conditions. A daily cap, one sending domain or the provider's logo on every email can matter more than the monthly headline, so the comparison quotes them wherever the provider states them. Some of these providers pay StartupPerks a referral commission, and their links are labeled as referral links; that never decides whether or where a provider appears, and no provider pays for a placement on this page.
Read the full methodologyCommon questions
Is there a free transactional email service?
Yes. Resend, Mailtrap, SMTP2GO, Mailjet, Brevo, Elastic Email, AhaSend, Plunk, Bird (formerly SparkPost), Postmark, Mailgun, MailerSend and Scaleway all have a plan that sends some email for free every day or month, by API or SMTP. Their limits differ a lot, from 100 emails a month to 300 a day, so the comparison on this page lists each one's daily and monthly caps, domains and conditions.
Does SendGrid still have a free plan?
Not for new accounts. Twilio SendGrid now gives new accounts a 60-day free trial that sends 100 emails a day, and sending stops when the trial ends unless you upgrade. Accounts created before March 25, 2025 may keep the old free plan. The SendGrid entry on this page quotes SendGrid's own pricing and help pages.
Is Amazon SES free?
Not as a standing free plan. New AWS customers get up to $200 in AWS Free Tier credits that can pay for Amazon SES, and after that new SES accounts pay $0.16 per 1,000 emails on the default Essentials plan, or $0.10 a la carte. New SES accounts start in a sandbox that sends only to verified addresses, 200 messages a day, until AWS grants production access.
Which free email API sends the most emails?
By the numbers each provider states, Brevo's free plan allows the most a day (300, about 9,000 a month) and Mailjet the most a month among the monthly plans (6,000, at most 200 a day), followed by Mailtrap (4,000 a month, 150 a day). Both Brevo and Mailjet put their own branding on free emails, which the transactional APIs here do not state they add.
Do free email APIs need a credit card?
Most of the free plans compared here need no card. MailerSend asks for card details on its free plan to prevent abuse without charging it, Scaleway needs a valid card on the account, and Mailgun sends only to a few authorized recipients until a card is on file. Each provider's entry quotes what its own page says.
Can I use a free email API for marketing emails?
Some, not all. Several services here are for transactional email only (Zoho CPaaS and Scaleway say so), while Brevo and Mailjet include marketing campaigns on their free plans and AhaSend and Plunk allow opted-in marketing email. None of them allows unsolicited email: send only to people who asked to hear from you.
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