TRANSACTIONAL EMAILS: WHAT THEY ARE AND WHAT THEY'RE NOT

Summary from the TLDR Marketing newsletter

A guide to what transactional emails are and are not, and the related compliance requirements. Transactional emails include order or shipping confirmations, order refund notifications, password resets, or customer service replies. Triggered emails, which are not transactional emails, include order renewal reminders, back-in-stock notifications, abandoned cart emails, and birthday/anniversary notifications. Transactional emails do not need an unsubscribe link. For customers in the U.S., no more than 20% of a transactional email should be promotional messaging.