Email infrastructure guide
Transactional Email API Guide
A practical guide to sending passwords, receipts, alerts, and other product-triggered email reliably.
Transactional email is triggered by a user or system action: a password reset, receipt, verification link, alert, or status update. It should be sent from a verified identity, be observable, and remain separate from promotional mail.
What this means in practice
- Action-triggered messages such as receipts and password resets
- Verified sender identities and aligned SPF, DKIM, and DMARC
- Per-message delivery responses and event records
- Clear separation between transactional and promotional use
Implementation checklist
- List every product event that must result in an email.
- Define a stable template and idempotency strategy for each event.
- Verify the sending domain before enabling production sends.
- Monitor bounces and complaints, then suppress unsafe destinations.
Questions teams ask
What counts as transactional email?
Messages needed to complete or communicate about a user action, such as account verification, receipts, security alerts, and password resets.
Can I send marketing email through a transactional API?
Only if the provider and recipient-consent model support it. Keep promotional traffic, opt-outs, and reputation controls separate from product-critical mail.