# Free Transactional Email APIs for Indie Makers in 2026

> Free transactional email API plans compared: send limits, paid entry prices, custom domains and commercial-use terms for 13 vendors, checked 22 Oct 2026.

- Canonical: https://zeroraised.com/blog/free-transactional-email-api
- Published: 2026-11-04T00:00:00Z
- Author: Jay Mokashi (https://zeroraised.com/blog/authors/jaymokashi)
- Publisher: ZeroRaised (https://zeroraised.com/)
- Section: Building
- Tags: developer-tools, comparison, bootstrapping

For a free transactional email API, the main options with a free plan are Resend, whose free plan lists 3,000 emails / mo and 100 emails a day ([Resend pricing](https://resend.com/pricing)), Postmark at 100 emails/month ([Postmark pricing](https://postmarkapp.com/pricing)), Mailgun at 100 emails per day ([Mailgun pricing](https://www.mailgun.com/pricing/)) and MailerSend at up to 500 emails per month ([MailerSend pricing](https://www.mailersend.com/pricing)). Amazon SES and SendGrid have no free tier, only credits or a trial. Every figure here is from the ZeroRaised [email tiers dataset](https://zeroraised.com/data/email-tiers), built from each vendor's own pages and checked 22 Oct 2026.

**Disclosure:** ZeroRaised publishes this guide and the email tiers dataset it draws on, and appears in the final section. Every limit, price and terms quote below comes from that dataset, which was built only from each vendor's own pricing, docs and terms pages. Each vendor fact links to the vendor page it came from, and those pages were fetched again on 22 Oct 2026. Where the dataset says a value is not stated, so does this guide. ZeroRaised has no affiliate deal with any company named here.

## TL;DR

Free email-sending plans for indie makers, from each vendor's own pages, checked 22 Oct 2026:

| Vendor | Free allowance as the vendor writes it | Main catch | Source |
|---|---|---|---|
| Resend | 3,000 emails / mo; 100 emails a day | Commercial-use rule not stated | [Resend pricing](https://resend.com/pricing) |
| Postmark | 100 emails/month | "No overages allowed in this plan." | [Postmark pricing](https://postmarkapp.com/pricing) |
| Mailgun | 100 emails per day | No monthly figure published; 1 user per account | [Mailgun pricing](https://www.mailgun.com/pricing/) |
| MailerSend | up to 500 emails per month | Card required on Free | [MailerSend pricing](https://www.mailersend.com/pricing) |
| SMTP2GO | up to 1,000 emails per month | Terms call free accounts "primarily for trial purposes" | [SMTP2GO pricing](https://www.smtp2go.com/pricing/) |
| Amazon SES | n/a (no free tier) | AWS credits only; paid sending at $0.16 per 1,000 emails | [SES pricing](https://aws.amazon.com/ses/pricing/) |
| SendGrid (Twilio) | n/a (no free tier) | Trial: 100 emails/day for 60 days | [Twilio Email API pricing](https://www.twilio.com/en-us/products/email-api/pricing) |

Brevo, Mailjet, Loops and Plunk mix marketing and app email, and Buttondown and EmailOctopus are newsletter tools; all are in the full table below. If your product will charge money, read the commercial-use section before you pick.

## What the dataset found, checked 22 Oct 2026

On 22 October 2026, ZeroRaised checked the free plans of 13 email-sending services that indie developers often use for transactional email, newsletters or both, and published the results as the [email tiers dataset](https://zeroraised.com/data/email-tiers). It records the free monthly and per day send limits, the paid entry price as the vendor shows it, custom domain on free and what the terms say about commercial use. All 27 cited vendor URLs returned HTTP 200 when fetched.

Three findings matter most for sign-up and password reset emails:

- **Two well-known services have no free tier.** Amazon SES lists "$0.16 per 1,000 emails" and offers only AWS Free Tier credits ([SES pricing](https://aws.amazon.com/ses/pricing/)). SendGrid's pricing now sits on Twilio's site and offers a "Free trial lets you send 100 emails/day for 60 days" ([Twilio Email API pricing](https://www.twilio.com/en-us/products/email-api/pricing)).
- **Limits are not counted the same way.** Some vendors cap per month, some per day, one per rolling 30 days and some by subscribers. The dataset does not convert them, and neither does this guide.
- **Most free plans say nothing about commercial use.** Seven of the 11 vendors with a free plan have no commercial-use rule in the terms the dataset checked. The four that do say quite different things.

The dated event here is the check itself: a snapshot of what each vendor published on 22 Oct 2026. None of the pricing pages fetched that day showed a dated plan or price change from the previous two weeks, so there is no vendor announcement to add.

## Free transactional email API plans compared: all 13 vendors

This is the full dataset in one table, with values as each vendor writes them, spacing and units included. "not stated" means the vendor's pages that were checked did not state the value; it does not mean "no limit", "allowed" or "not allowed".

| Vendor | Free monthly send limit | Per day limit | Paid entry price (as shown) | Custom domain on free | Commercial use (terms) | Source |
|---|---|---|---|---|---|---|
| Resend | 3,000 emails / mo | 100 emails a day | Pro $20 / mo (50,000 emails / mo) | Yes: 3 domains | not stated | [Resend pricing](https://resend.com/pricing) |
| Postmark | 100 emails/month | Unlimited (comparison table, Free column) | Basic $15.00 /mo | Yes: Up to 10 domains (comparison table, Free column) | Licence for personal use, or a business communicating with its contacts; free plan not named | [Postmark pricing](https://postmarkapp.com/pricing), [Postmark terms](https://postmarkapp.com/terms-of-service) |
| Amazon SES | n/a (no free tier) | n/a (no free tier) | $0.16 per 1,000 emails | n/a (no free tier) | n/a (no free tier) | [SES pricing](https://aws.amazon.com/ses/pricing/) |
| Mailgun | not stated | 100 emails per day | Basic Starting at $ 15 /mo (10,000 emails/mo included) | Yes: 1 custom sending domain | not stated | [Mailgun pricing](https://www.mailgun.com/pricing/) |
| SendGrid (Twilio) | n/a (no free tier) | n/a (no free tier) | Essentials starting at $19.95/mo | n/a (no free tier) | n/a (no free tier) | [Twilio Email API pricing](https://www.twilio.com/en-us/products/email-api/pricing) |
| Brevo | not stated | 300 emails per day | Starter: "price":"9","priceCurrency":"USD" (JSON-LD only) | not stated | not stated | [Brevo pricing](https://www.brevo.com/pricing/) |
| MailerSend | up to 500 emails per month | not stated | Hobby $7.00 /month (5,000 emails /month) | Yes: 1 domain | "strictly for commercial use" | [MailerSend pricing](https://www.mailersend.com/pricing), [MailerSend terms](https://www.mailersend.com/legal/terms-of-use) |
| Loops | 4,000 sends per 30 days (rolling, first 1,000 contacts) | not stated | Growth $49 / month | not stated | not stated | [Loops pricing](https://loops.so/pricing) |
| Plunk | 1,000 emails / mo | not stated | Pay as you grow $0.001 / email | Yes: "Custom domains" listed on Free | not stated | [Plunk pricing](https://www.useplunk.com/pricing) |
| Buttondown | not stated (free for the first 100 subscribers) | not stated | Basic: "price":"9","priceCurrency":"USD" (JSON-LD only; billing period not stated) | Yes: "Send from a custom domain" | not stated | [Buttondown pricing](https://buttondown.com/pricing) |
| SMTP2GO | up to 1,000 emails per month | not stated | Starter $ 10 /mo $ 100 /year (page title: "Plans From $15/mo") | not stated | Free plan accounts "primarily for trial purposes" | [SMTP2GO pricing](https://www.smtp2go.com/pricing/), [SMTP2GO terms](https://www.smtp2go.com/terms/) |
| Mailjet | 6,000 emails/month | 200 emails per day | Starter $ 9 /month (8,000 emails/month) | not stated | not stated | [Mailjet pricing](https://www.mailjet.com/pricing/) |
| EmailOctopus | 10,000 emails per month | not stated | PRO $ 9 PER MONTH, BILLED YEARLY | not stated | "not intended for personal use" | [EmailOctopus pricing](https://emailoctopus.com/pricing), [EmailOctopus terms](https://emailoctopus.com/legal/terms) |

A few readings in that table need care, and the dataset flags each one:

- **Units differ.** Loops counts "sends per 30 days" on a rolling basis, marketing and transactional together. Buttondown prices by subscribers, and its free plan is "Absolutely nothing for your first 100 subscribers." ([Buttondown pricing](https://buttondown.com/pricing)). EmailOctopus and Loops also cap contacts or subscribers.
- **Two prices exist only in embedded data.** Brevo's and Buttondown's visible prices are rendered by JavaScript, so the static page carries them only in schema.org JSON-LD, which is what the table quotes ([Brevo pricing](https://www.brevo.com/pricing/), [Buttondown pricing](https://buttondown.com/pricing)). Buttondown's JSON-LD gives no billing period.
- **Postmark's per day figure and domain count come from its comparison table.** The table's columns read "Features Free Basic Pro Platform", and the Free column shows Unlimited for the per day row and "Up to 10 domains" for custom sending domains ([Postmark pricing](https://postmarkapp.com/pricing)).
- **Some prices are yearly by default.** MailerSend, SMTP2GO and EmailOctopus show yearly prices on first load. SMTP2GO's card says "Starter $ 10 /mo $ 100 /year" while its page title says "Plans From $15/mo" ([SMTP2GO pricing](https://www.smtp2go.com/pricing/)); both are kept.

The paid entry price column shows the size of the next step, not a comparison; first paid plans differ as much as free ones.

## Transactional or marketing: what each free plan is built for

A transactional email is one your app sends because a user did something. Resend's pricing page puts it plainly: "Transactional emails are typically triggered by user actions and include things like password resets or order confirmations. Marketing emails are typically sent to a list of contacts and include things like newsletters or promotional campaigns." ([Resend pricing](https://resend.com/pricing)).

Vendors build, count and price the two differently. The table describes each in the vendor's own words; it is not a judgement of deliverability.

| Vendor | How the vendor's page describes sending | Source |
|---|---|---|
| Resend | Transactional emails "sent using the /emails API", marketing via "the /broadcasts API" | [Resend pricing](https://resend.com/pricing) |
| Postmark | "transactional and marketing emails never mix"; Message Streams are "completely separate sending infrastructures" | [Postmark pricing](https://postmarkapp.com/pricing) |
| Mailgun | Page title: "Transactional Email API Service For Developers" | [Mailgun pricing](https://www.mailgun.com/pricing/) |
| MailerSend | "Email API and SMTP relay" | [MailerSend pricing](https://www.mailersend.com/pricing) |
| SMTP2GO | Plans sized by "How many emails do you send per month?" | [SMTP2GO pricing](https://www.smtp2go.com/pricing/) |
| Brevo | "Send real-time email, SMS, & WhatsApp messages triggered via SMTP relay and API." | [Brevo pricing](https://www.brevo.com/pricing/) |
| Mailjet | "APIs, SMTP Relay, Webhooks" | [Mailjet pricing](https://www.mailjet.com/pricing/) |
| Loops | "4,000 total marketing and transactional sends per rolling 30 days" | [Loops pricing](https://loops.so/pricing) |
| Plunk | "Open-source email platform for transactional, marketing, and automation." | [Plunk pricing](https://www.useplunk.com/pricing) |
| Amazon SES | "Send transactional and marketing email at scale using the SES API, SMTP interface, or an AWS SDK." | [SES pricing](https://aws.amazon.com/ses/pricing/) |
| Buttondown | "Build your newsletter" | [Buttondown pricing](https://buttondown.com/pricing) |
| EmailOctopus | "Sign up and send your first campaign in minutes." | [EmailOctopus pricing](https://emailoctopus.com/pricing) |

If your product only needs sign-up confirmations, magic links and receipts, the API-first group is where to look. If you also want a product newsletter from the same account, the mixed platforms put both in one place, but on Loops and Plunk the two kinds draw from one allowance, so a big announcement can eat into what is left for password resets.

## API-first senders: Resend, Postmark, Mailgun, MailerSend and SMTP2GO

These five are the closest fit to the keyword: an API or SMTP relay you call from your app, with a free allowance attached.

### Resend

Resend's free plan lists "3,000 emails / mo", "100 emails a day" and "3 domains", and the paid step is "Pro $20 / mo" for "50,000 emails / mo" ([Resend pricing](https://resend.com/pricing)). Asked about a trial, the page says "No, but we provide a free-forever plan." The terms add that "You are not required to provide billing information to use the Free Tier." ([Resend terms](https://resend.com/legal/terms-of-service)). The dataset found no commercial-use rule in Resend's terms or acceptable use policy.

The number to watch is the per day cap: a busy launch afternoon can reach 100 emails a day long before 3,000 a month ([Resend pricing](https://resend.com/pricing)).

### Postmark

Postmark's Free plan is "$0.00 /mo" to "Test your integration with 100 emails/month", and "No overages allowed in this plan." ([Postmark pricing](https://postmarkapp.com/pricing)). The page calls it the "free Developer plan" that "never expires or runs out", yet labels its button "Start Free Trial". The dataset keeps both wordings. The paid step is "Basic $15.00 /mo For solo developers and smaller teams". At 100 emails a month with no overages, the free plan is, in Postmark's own words, for testing an integration.

### Mailgun

Mailgun's Free plan is "$ 0 /mo" with "100 emails/day included", "1 custom sending domain" and "Free plans are limited to 1 user per account." ([Mailgun pricing](https://www.mailgun.com/pricing/)). It publishes a per day cap only, so the monthly cell reads not stated. The paid step is "Basic Starting at $ 15 /mo 10,000 emails/mo included".

### MailerSend

MailerSend says "This plan lets you send up to 500 emails per month for free!" ([MailerSend pricing](https://www.mailersend.com/pricing)). Free also has "1 template, 1 domain, 1 user (plus 1 accountant), 1 API token, 1 webhook", plus a cap of 100 API requests per day. That is an API request limit, not a send limit, so the per day send cell reads not stated. MailerSend asks for a card on Free "to prevent abuse of the platform", and the paid step is "Hobby For personal projects and side hustles" at "7.00 /month" for "5,000 emails /month".

### SMTP2GO

SMTP2GO offers "our free plan for up to 1,000 emails per month" with "No credit card required"; reporting is "Limited to 14 days for the free plan." ([SMTP2GO pricing](https://www.smtp2go.com/pricing/)). The yearly view shows "Starter $ 10 /mo $ 100 /year" while the page title says "Plans From $15/mo"; both are kept.

## Marketing platforms with an API: Brevo, Mailjet, Loops and Plunk

These four send app email and newsletters from one account.

### Brevo

Brevo's free plan is "Free forever, no credit card needed" ([Brevo pricing](https://www.brevo.com/pricing/)). The sending limit comes with a condition: "Once we approve your account for sending, you can start sending up to 300 emails per day." Its pricing page states no monthly figure for Free.

The Starter offer in the page's JSON-LD reads "name":"Starter","price":"9","priceCurrency":"USD", and the Starter card says "From 5,000 emails per month" ([Brevo pricing](https://www.brevo.com/pricing/)). Brevo's terms also say: "We may suspend, limit, or terminate the free Services for any reason at any time without notice." ([Brevo terms](https://www.brevo.com/legal/termsofuse/)).

### Mailjet

Mailjet's free plan reads "Free $ 0 /month 6,000 emails/month 200 emails per day", with "1,000 contacts" ([Mailjet pricing](https://www.mailjet.com/pricing/)). The paid step is "Starter $ 9 /month 8,000 emails/month", with no per day limit.

### Loops

Loops counts in a unit no other vendor in the dataset uses. The free plan "includes 4,000 total marketing and transactional sends per rolling 30 days to your first 1,000" contacts, at "Up to 10 emails per second" ([Loops pricing](https://loops.so/pricing)). "Free emails include Loops branding." Loops "is free to start, with no credit card required", and the paid step is "Growth $49 / month". Pricing is per subscribed contact, and a rolling window never resets on the first of the month.

### Plunk

Plunk's free plan is "Free forever 1,000 emails / mo No credit card required", and its pricing page sums it up as "Free plan: 1,000 emails per month. Paid plan: $0.001 per email." ([Plunk pricing](https://www.useplunk.com/pricing)). "Custom domains" are listed on Free, and so is "Plunk branding on emails". Plunk's terms describe the free tier as "1,000 emails/month total across all email types" ([Plunk terms](https://www.useplunk.com/terms)). Plunk is also open source; the page offers "Self-host for free".

## Newsletter tools in the dataset: Buttondown and EmailOctopus

Buttondown and EmailOctopus are in the dataset because indie makers often reach for them for product updates, not because they are transactional APIs. Their free plans are set by subscribers.

**Buttondown** charges "Absolutely nothing for your first 100 subscribers", and that plan includes "Send from a custom domain" ([Buttondown pricing](https://buttondown.com/pricing)). The page's JSON-LD lists "Basic plan - Up to 1000 subscribers" at a price of 9 USD, with no billing period stated. Buttondown also says "All of these prices assume that you're sending at most one email a day to your entire subscriber base." Its terms do use the words "non-commercial", but only for "personal, non-commercial transitory viewing" of website materials ([Buttondown terms](https://buttondown.com/legal/terms)), not for the sending service, so the commercial-use cell reads not stated.

**EmailOctopus** offers "STARTER Free 2,500 subscribers 10,000 emails per month EmailOctopus branding on emails" ([EmailOctopus pricing](https://emailoctopus.com/pricing)). "We don't offer a free trial, however we'd recommend starting on our free plan", with "no credit card needed". The paid step is "PRO $ USD $ 9 PER MONTH, BILLED YEARLY". Its terms say it "is built for organisations" and "is not intended for personal use" ([EmailOctopus terms](https://emailoctopus.com/legal/terms)).

Either can carry a launch announcement; neither is the place for a password reset.

## No free tier: Amazon SES and SendGrid

**Amazon SES** has no SES free allowance on its pricing page. It lists "$0.16 per 1,000 emails" on the Essentials plan, and says "New AWS customers will receive up to $200 in AWS Free Tier credits, which can be applied towards eligible AWS services, including Amazon Simple Email Service." ([SES pricing](https://aws.amazon.com/ses/pricing/)). It also says "The free plan will be available for 6 months after account creation." and "All Free Tier credits must be used within 12 months of your account creation date." The [AWS Free Tier](https://aws.amazon.com/free/) page adds "The account closes on its own 6 months after you open it or when your credits run out". Credits shared across AWS are not a free email plan.

**SendGrid** sends visitors from its own pricing URL to Twilio, where the [Email API pricing page](https://www.twilio.com/en-us/products/email-api/pricing) shows "Free Trial $0/mo for 60 days Essentials starting at $19.95/mo". The trial "lets you send 100 emails/day for 60 days". After that, it is a paid plan or nothing.

## Commercial use on free email plans: what the terms say

The dataset searched each vendor's terms (and Resend's acceptable use policy) for a commercial-use rule. Four state one. They are quoted here exactly as the dataset gives them:

| Vendor | What the terms say | Source |
|---|---|---|
| MailerSend | "You acknowledge that the Services are strictly for commercial use and that you are not authorized to use the Services for personal, family, or household purposes." | [MailerSend terms](https://www.mailersend.com/legal/terms-of-use) |
| EmailOctopus | "EmailOctopus is built for organisations, and we ask you to use it for purposes relating to your trade, business, craft or profession. It is not intended for personal use." | [EmailOctopus terms](https://emailoctopus.com/legal/terms) |
| SMTP2GO | "Free plan accounts are primarily for trial purposes and for sending low amounts of email. Businesses must not create more than 10 free plan accounts." | [SMTP2GO terms](https://www.smtp2go.com/terms/) |
| Postmark | Licence "to access and use our Service and the AC PM Content in accordance with the Terms for (i) Your own personal use or (ii) if You are a business or organization, to communicate about your business or organization with your Contacts." (all plans; free plan not named) | [Postmark terms](https://postmarkapp.com/terms-of-service) |
| Resend, Mailgun, Brevo, Loops, Plunk, Buttondown, Mailjet | not stated | Each vendor's terms page, listed in the dataset |
| Amazon SES, SendGrid | n/a (no free tier) | [SES pricing](https://aws.amazon.com/ses/pricing/), [Twilio Email API pricing](https://www.twilio.com/en-us/products/email-api/pricing) |

None is a simple yes or no for a free plan. MailerSend and EmailOctopus rule out personal use rather than business use. SMTP2GO frames free accounts as mainly for trials and small volumes. Postmark's licence does not single out the free plan.

For the seven not stated rows, the terms that were checked had no rule either way. Not stated is not permission. If revenue depends on the answer, ask the vendor in writing and keep the reply. The same caution applies to hosting: the sibling [free tiers dataset](https://zeroraised.com/data/free-tiers) records what hosting and database vendors say about commercial use on their free plans.

## Per day caps and launch day

A per day cap is the limit most likely to bite a small product, because a launch post can bring a crowd in one afternoon, each person triggering a confirmation. Four free plans publish a per day cap: [Resend](https://resend.com/pricing) (100 emails a day), [Mailgun](https://www.mailgun.com/pricing/) (100 emails per day), [Mailjet](https://www.mailjet.com/pricing/) (200 emails per day) and [Brevo](https://www.brevo.com/pricing/) (300 emails per day, once approved). For the others it is not stated, which is not the same as none.

Before launching on a capped plan, count how many emails one new user triggers (a confirmation, a welcome, a magic link at each login) and compare that with the cap. Decide what happens when the cap is reached: does sign-up still work, and can you resend later? If the numbers are close, upgrade before launch day. [How to handle traffic spikes](https://zeroraised.com/blog/how-to-handle-traffic-spikes) covers what else to check on third-party services before a spike, and if you are collecting sign-ups early, [how to build a waitlist before launch](https://zeroraised.com/blog/how-to-build-a-waitlist-before-launch) covers a flow whose confirmations count against the same allowance.

## How to choose a free transactional email API for a small product

The dataset does not rank vendors. These questions sort the options for a particular product.

**What will the free plan send?** List every email your app sends and its trigger: sign-up confirmation, password reset, receipt, invite. With magic links or email codes, every sign-in is an email; [passkeys vs passwords for SaaS](https://zeroraised.com/blog/passkeys-vs-passwords-for-saas) covers how the login method changes that. Then decide whether announcements share the account. On Loops and Plunk they share one pool.

**Which limit will you meet?** Check the per day cap, the monthly allowance and the domain count. Mailgun's free plan has "1 custom sending domain" ([Mailgun pricing](https://www.mailgun.com/pricing/)) and MailerSend's "1 domain" ([MailerSend pricing](https://www.mailersend.com/pricing)), which is tight if you run several products from one account.

**What else is on the email?** Loops, Plunk and EmailOctopus add their branding on free plans ([Loops pricing](https://loops.so/pricing), [Plunk pricing](https://www.useplunk.com/pricing), [EmailOctopus pricing](https://emailoctopus.com/pricing)). Decide whether that is acceptable on a receipt.

**What does the vendor need to start?** MailerSend asks for a card on Free, and Brevo sends only "Once we approve your account for sending" ([Brevo pricing](https://www.brevo.com/pricing/)). Both change how quickly you can test.

**What does the next step cost?** Know the paid entry price before you need it, so the email plan can sit in your monthly costs alongside hosting.

**Is the key safe?** A sending API key can send as your domain. Keep it out of client-side code and the repo; the [vibe coded app security checklist](https://zeroraised.com/blog/vibe-coded-app-security-checklist) covers exposed secrets.

## Where ZeroRaised fits

Email is easy to forget until a password reset fails to arrive. ZeroRaised keeps the [email tiers dataset](https://zeroraised.com/data/email-tiers) for that reason: the free plans of 13 email-sending services, every figure linked to the vendor's own page, with a visible check date and a CSV download. The [ZeroRaised data hub](https://zeroraised.com/data) lists it with the other datasets. If a vendor's page has changed since 22 Oct 2026, the vendor's page wins.

[ZeroRaised](https://zeroraised.com/) is a free launch site for bootstrapped makers whose products have no institutional VC or accelerator equity. Once your app's emails arrive reliably, you can [submit it for review](https://zeroraised.com/submit). The [maker perks page](https://zeroraised.com/perks) lists separate offers for eligible makers, some of which cut running costs.

So, free transactional email APIs in one line: Resend, Postmark, Mailgun, MailerSend and SMTP2GO are API-first senders with free plans of different sizes, Brevo, Mailjet, Loops and Plunk mix marketing and app email, Amazon SES and SendGrid have no free tier, and whichever you choose, check the per day cap and the commercial-use terms before launch day.

## Frequently asked questions

### Which email APIs have a free plan in 2026?

Of the 13 services in the ZeroRaised email tiers dataset, checked 22 Oct 2026, 11 have a free plan: Resend, Postmark, Mailgun, Brevo, MailerSend, Loops, Plunk, Buttondown, SMTP2GO, Mailjet and EmailOctopus. Amazon SES and SendGrid have no free tier, only credits or a trial.

### Does SendGrid still have a free plan?

Not as a free plan. Twilio's Email API pricing page offers a free trial that lets you send 100 emails/day for 60 days, and the Essentials plan starts at $19.95 per month. The dataset records SendGrid as n/a (no free tier).

### Is Amazon SES free?

SES has no free allowance of its own on its pricing page. New AWS customers can get up to $200 in AWS Free Tier credits that can be applied to eligible services including SES, and the free plan is available for 6 months after account creation. SES itself lists $0.16 per 1,000 emails on the Essentials plan.

### Can I use a free email plan for a paid product?

Check the terms first. MailerSend's terms say its Services are strictly for commercial use, EmailOctopus says it is built for organisations and not intended for personal use, and SMTP2GO says free plan accounts are primarily for trial purposes. For Resend, Mailgun, Brevo, Loops, Plunk, Buttondown and Mailjet the dataset found no commercial-use rule, which is not the same as permission.

### What is the difference between transactional and marketing email?

Resend's pricing page puts it this way: transactional emails are typically triggered by user actions, such as password resets or order confirmations, while marketing emails are typically sent to a list of contacts, such as newsletters or promotional campaigns. Several vendors price or route the two separately, so check which kind your free plan covers.