Timing, subject lines, content structure, authentication and operations — the practices that decide whether your transactional email works or quietly fails.
The 15 transactional emails almost every product ends up sending — what each one must contain, what breaks it, and which ones are worth getting right first.
Consent, infrastructure, sender reputation and legal obligations all change depending on which one you are sending — and the line is thinner than most teams think.
What a transactional email is, how it differs from marketing email, the 15 most common types, and how sending actually works — from API call to inbox.