Which Transactional Emails Does My SaaS Need?

Your SaaS is taking shape, and Claude Code has started talking about transactional emails: the automatic, one-to-one messages your product sends when someone does something, like signing up or paying. If you've asked yourself "which transactional emails does my SaaS need?", this page gives you the answer.

You'll get the core set most SaaS products send, the extras that depend on your features, and a message to send Claude Code so it reviews your project and proposes a full email plan for you to approve.

Which transactional emails does my SaaS need?

Most SaaS products need seven: four account emails that any product with logins sends, plus three billing emails if you charge. Here they are, with when each one goes out.

The password changed email is often left out. OWASP, a nonprofit that publishes widely used web security guidance, recommends emailing users after their password has been reset, without ever including the password itself.

For a longer list with an example of each, see 12 transactional emails every SaaS needs.

Which emails depend on what your product does?

The rest of your list comes from your features. Anything that involves another person, a deadline or a change of status usually adds an email.

If you take payments with Stripe, check what Stripe already sends. From its own settings, Stripe can email customers receipts, failed payment notices, trial ending reminders and cancellation notices, among others. For each one, decide whether Stripe sends it or your SaaS does, so nobody gets two receipts for one payment. Our guide to sending your own emails after a Stripe payment explains the choice.

Keep the list to emails people need. In the US, the Federal Trade Commission's CAN-SPAM guide counts an email as transactional when it confirms something the person already agreed to, gives security information, or tells them about a change to their account or subscription. An email whose main job is to promote something is marketing, even when it goes to existing customers. If you're unsure about one, see transactional vs marketing emails.

How do you ask Claude Code to plan your emails?

Ask Claude Code to look through your project and propose the list. It can see your sign-up flow, your login page, your billing setup and your features, so it can work out which moments in your product need an email, rather than working from a generic checklist.

If SimpleSends isn't connected yet, connect it first so Claude Code can build and test the emails once you approve the plan. A connector is a link in Claude Code's settings that lets it work with an outside service while you build. To connect SimpleSends:

1. Sign up on the SimpleSends website and follow the steps there to set up the email address you'll send from. To send from your own domain, this includes adding a few DNS records where your domain is registered. DNS records are the settings that tell the internet which services can act for your domain.
2. In Claude Code, open Customize, then Connectors, choose Add, then Add custom connector. Name: SimpleSends. MCP server URL: https://mcp.simplesends.com/mcp
3. When Claude prompts you to connect, log in to SimpleSends.
4. Back in the Claude Code chat, tell Claude Code: "I've connected SimpleSends for all transactional email." It takes it from there, including adding what your project needs to send email.

For the full walkthrough, see how to send emails from Claude Code. Then brief Claude Code the way you'd brief someone joining your team:

Before we build any emails, look through my project and make a plan of every transactional email it should send. For each one, tell me who gets it, what triggers it and why we need it. Include anything Stripe already sends so we don't double up, and ask me about anything you're not sure of. Don't build anything yet.

Claude Code reads through your project and comes back with a list, usually as a table, along with a few questions about choices only you can make.

What does an email plan look like?

Say your SaaS is a project-management tool for small teams, with a 14-day free trial, paid plans through Stripe and team accounts. Claude Code's plan might look like this:

Underneath, Claude Code might ask: should Stripe keep sending receipts, or should your SaaS send them in your own design? And would you like an email each time someone new signs up?

How do you review and approve the plan?

Read the plan the way you'd review a proposal from a person on your team. Four questions cover most of it:

1. Is anything missing? Picture a new user's first month: signing up, inviting a colleague, forgetting their password, paying, changing plan. Every moment where they'd expect to hear from you should have an email.
2. Is every email transactional? Anything that mainly promotes something belongs in a separate, opt-in list, not this plan.
3. Who sends each billing email? Settle Stripe versus your SaaS for receipts, failed payments and trial reminders.
4. Who gets each one? Most go to users, some go to teammates, and a few, like sign-up alerts, go to you.

When you're happy, approve it with any changes:

The plan looks good. Let Stripe keep sending receipts, add a sign-up alert to me, and keep the trial reminder at three days before the trial ends. Save the plan in the project so we can work through it, then start with the confirm-your-email message.

Claude Code updates the plan, saves it in your project and moves on to the first email. Because the plan lives in your project, you can ask Claude Code to add to it whenever you add a feature.

What happens after you approve the plan?

With the list agreed, the next steps are design, wording and timing. Claude Code can design emails that match your brand, write them the way a copywriter would from your brief, and set each one to go out at the right moment. You'll see test emails in the chat first. Once your SaaS is live, real emails go out from your project automatically whenever someone signs up, resets a password or pays.

For the whole journey from plan to sending, see transactional emails in Claude Code.