Transactional email examples: 12 emails every product sends, and what makes each one work

Search for "transactional email examples" and most results are screenshots. A screenshot shows the layout and hides the part that decides whether the email works: what triggers it, what it must say, and what breaks it. Here are twelve emails with those details.

1. One-time passcode

Subject: Your Acme verification code Must contain: the code, its lifetime, and what to do if the user did not ask for it. Usual mistake: guessable codes. Generate them with a cryptographically secure random source. The full OTP workflow covers hashing, expiry and attempt limits.

2. Email verification link

Subject: Confirm your email address Must contain: one button, an expiry, and a plain-text link. Usual mistake: letting a mail scanner use up the token by opening the link. Make the page ask for a click. See email verification.

3. Welcome

Subject: Welcome to Acme, Ada Must contain: the one thing a new user should do first. Usual mistake: sending it before the address is verified, so you mail someone who mistyped. Details in welcome email.

4. Password reset

Subject: Reset your Acme password Must contain: a single-use link, a short expiry, and "ignore this if it was not you". Usual mistake: revealing whether an account exists. Respond identically either way. See password reset email.

5. Security alert

Subject: New sign-in to your account Must contain: what happened, when, roughly where, and how to lock the account. Usual mistake: including a link that acts. Link to a page that needs a login. See security alerts.

6. Receipt

Subject: Your receipt from Acme (order 1042) Must contain: amount, currency, date, what was bought, last four card digits. Usual mistake: sending it twice when the payment provider redelivers an event. Record the event ID first. See payment confirmation.

7. Invoice

Subject: Invoice INV-1042 from Acme Must contain: the number in the subject, so accountants can search for it, and a link to the PDF. Usual mistake: relying on an attachment. Use a hosted link that expires after days, not minutes. See invoice email.

8. Order confirmation

Subject: Order 10482 confirmed Must contain: items, totals, delivery address, how to contact you. Usual mistake: unescaped customer text in the item table. See order confirmation.

9. Shipping notification

Subject: Your order has shipped Must contain: carrier, a tracking link that works, a realistic estimate. Usual mistake: a precise date nobody can keep. See shipping notification.

10. Booking confirmation and reminder

Subject: Booking confirmed: Haircut on Friday Must contain: date, time and time zone, location, and a way to change it. Usual mistake: no time zone. See booking confirmation and reminders.

11. Team invitation

Subject: Grace invited you to Acme Must contain: who invited you, to what, with which role, and when it expires. Usual mistake: letting the inviter's display name pose as someone else. See team invitations.

12. Failed payment

Subject: Your payment did not go through Must contain: what failed, what happens next and when, and a link straight to the billing page. Usual mistake: a threatening tone. Most failures are expired cards. See subscription emails.

What the twelve share

• One trigger, one email. Each fires from a server-side event, never from a page load.
• One action. A single button or code.
• Plain-text part and a stable sender. Same From address and subject pattern each time.
• A guard against duplicates. The Inboxili API has no idempotency key, so record "already sent" in your own database. The idempotency article shows how.
• No promotion. Offers go in campaigns, not in these.

If you are planning the set for a new product, build them in the order above. The first six cover almost every launch.