What is a transactional email? (e.g., password reset, order confirmation)

Someone buys something from your store at 11pm and immediately checks their inbox. They're not hoping for a newsletter. They want their order confirmation. That email they're expecting? That's a transactional email.

A transactional email is triggered by something a specific person did, and it delivers information they need as a direct result of that action. It's a one-to-one message, not a one-to-many broadcast.

The most common types you'll send or receive:

• Account emails: Password resets, email verification links, security alerts, account changes.
• Purchase emails: Order confirmations, receipts, invoices, shipping notifications, delivery confirmations.
• Service emails: Appointment reminders, booking confirmations, ticket delivery, reservation updates.

What they all have in common is that the recipient asked for them, at least indirectly. They took an action that made the email necessary. That's what separates transactional from marketing email, which the sender initiates to promote something.

This distinction matters more than most people realize. Transactional emails have different rules under laws like CAN-SPAM and GDPR (they're generally exempt from the opt-out requirements that apply to marketing email). They also perform very differently in deliverability terms. Recipients open them fast and reliably, which is why mixing promotional content into transactional emails is a tempting but genuinely risky move. (More on that in this question about including marketing content.)

If you're sending transactional email at any volume, it's worth keeping it on a separate sending stream from your marketing. A complaint spike from a campaign shouldn't delay your password reset emails.