Free Transactional Email Service Plans Compared (2026)

Most email services let you start for free. The catch is in the details. Some free plans cap you at 100 emails a day, some end after 60 days, and some won't send to your customers until a person has reviewed your account.

This guide compares every free transactional email service plan worth knowing about, as of October 2026. A transactional email is a one-to-one message your product sends because of something a person did, like signing up or resetting a password. (New to the term? Start with what a transactional email service is.)

You'll see what each free plan includes, the limits that tend to cause problems, and how to tell when it's time to pay. It's written for people building a SaaS, site or tool with Claude Code who want to start without a monthly bill.

Free transactional email service plans compared

Here's what each free plan includes today. Every number comes from the provider's own pricing page, checked October 5, 2026.

Two things stand out. First, a monthly number and a daily number aren't the same. Resend's 3,000 a month only works if your emails are spread out, because no single day can go over 100.

Second, a trial isn't a plan. SendGrid's free option ends after 60 days. Amazon SES charges per email once your credits run out.

Which free plan limits catch people out?

The headline allowance is rarely the problem. These are the limits that most often stop emails going out.

Daily caps. A launch, a post that takes off or a batch of team invites can pass 100 emails in an afternoon. On a free plan, the extra emails usually wait until the next day, including password resets people are waiting for. Postmark allows no overages on its free plan, and Resend's pay-as-you-go extras are only for paid plans. Brevo holds up to 1,000 extra transactional emails in a retry queue, then stops delivering.

Account approval and sandboxes. Postmark reviews every new account by hand. Until it approves yours, you can only send to the domains you've added and verified. Amazon SES starts every new account in a "sandbox": you can send only to verified addresses, at most 200 messages a day and one a second, until you request production access. AWS says it replies to those requests within 24 hours. Leave time for this before launch day.

Trials that end. SendGrid's trial lasts 60 days. If you set it up early in your build, it may run out before you have real users.

Branding in your emails. Brevo and Loops add their own footer to emails sent on the free plan. That's fine for testing, but you may not want it in a receipt or a password reset.

Short logs. Logs are the record of what was sent and whether it arrived. Mailgun's free plan keeps them for 1 day, so a "never got the email" question about yesterday can be hard to answer. Resend keeps data for 30 days. Logs are how you check whether your emails actually sent.

Domain limits. Every service asks you to verify the domain you send from by adding a few DNS records (the settings that tell the internet how your domain works). Free plans limit how many domains you can add: one on Mailgun and three on Resend. Our guide to verifying a domain for email walks through it.

How many emails will your SaaS actually send?

Most early SaaS products send fewer emails than founders expect, but they arrive in bursts. Here's a rough example for a product getting 30 new sign-ups a day.

That fits inside Resend's free allowance, under its daily cap, with little room to spare. Double the sign-ups and you'd pass 100 on most days. It's well past Postmark's 100 a month in the first two days.

Your own numbers depend on which emails your product sends. Claude Code can work this out from your project.

Look at my project and list every email it sends or should send. For each one, estimate how many would go out on a normal day and on a busy launch day, assuming 30 new sign-ups a day. Put it in a short table.

Claude Code reads through your project and gives you a table you can hold up against any free plan. If it finds emails you haven't built yet, see which emails your SaaS needs.

When should you upgrade from a free plan?

Upgrade before you hit a limit, not after. One missing password reset is a support ticket. A week of them costs you customers.

It's time to upgrade when:

1. You regularly send more than about 70% of your daily cap on a normal day.
2. You're about to launch, post publicly or import a list of existing users.
3. Your free option is a trial with an end date.
4. You need more sending domains, longer logs or more teammates.
5. You want the provider's footer out of your emails.

Here's the first paid step for each service, checked October 2026.

For prices at higher volumes, see how much transactional email costs.

What's the best free option for Claude Code users?

The best free plan is the one whose limits you won't hit before you'd be happy to pay. Beyond that, it comes down to who the service is built for.

If you write code yourself, or want to edit your sending code yourself, Resend's free plan is a strong start. Its allowance covers most early SaaS products, and its tools and docs are written for developers.

If you don't code, the allowance is only part of the picture. You'll work with your email service every time an email needs adding, changing or fixing. Developer services expect you to do that through their dashboards and docs.

SimpleSends is built for people who build with Claude Code but don't write code. You sign up once on the SimpleSends website and add it to Claude Code as a connector (an MCP server, which lets Claude Code use an outside service). From then on, you brief Claude Code in plain English. It designs, writes and builds your transactional emails, sends test emails from the chat, and reads your send logs to tell you whether an email went out. Real emails go out from your live project, not the chat. The Starter plan is free and covers up to 100 emails a day.

Check how many emails my project sent through SimpleSends this week, and tell me which days were busiest.

Claude Code looks at your send logs and tells you, in plain English, how many emails went out each day, so you can compare your busiest days with your plan's limits.