Transactional Email Template Generator: Create Triggered Email Specs

A transactional generator has a stricter job than a campaign generator. It must preserve what happened in the product and make the next action obvious without adding unsupported claims.

Event contract

event: payment.succeeded
event_id: pay_123
recipient: billing_contact_id
required: amount, currency, receipt_id, paid_at
optional: customer_name, product_name
exit: send once for this event_id

If the event ID or required fact is missing, the generator should return a blocker, not a confident draft.

Output sections

1. Purpose and message category.
2. Required and optional variables.
3. Subject, preheader, body, and plain text.
4. Fallback behavior.
5. Idempotency and retry behavior.
6. Suppression and state transitions.
7. Security and compliance notes.
8. QA fixtures.

Guardrails

• Never invent amounts, dates, status, or account consequences.
• Never expose secrets or full payment credentials.
• Never make a transactional message depend on a marketing preference.
• Do not include promotional blocks unless explicitly approved.
• Keep security and billing links authenticated.
• Make duplicate event behavior deterministic.

Example instruction

Create a payment receipt template from this event.
Use only supplied facts. Include amount, currency, receipt ID,
and paid time. Hide optional fields when missing.
Return suppression, retry, security, and QA notes.

Review checklist

Have product, engineering, and support review the output. Test pending, succeeded, failed, refunded, duplicate, missing-field, and unauthorized-recipient cases. A template is not ready because it sounds natural; it is ready when its state transitions are safe.

Distinguish event ownership

A transaction may pass through several states, and each should have one source of truth:

Give every event a stable ID, event timestamp, recipient identity, and schema version. The generator should flag a missing owner instead of creating a generic “your order is progressing” message.

Define delivery and retry behavior

Transactional generation should specify whether a message is sent once per event, replaced by a newer state, or allowed to repeat after a failed delivery. Keep provider retries idempotent. Do not make a customer wait for a campaign preference or digest schedule to receive a required notice.

For security and billing messages, avoid sensitive values in subject lines and never ask for credentials, full card numbers, or one-time codes by reply. Link to the authenticated product surface and include a support path for an unexpected event.

Keep promotion out by default

If a shared shell has a promotional module, the transactional template should explicitly disable it unless an approved policy allows it. Test a receipt with no marketing consent, a customer who opted out, and a message sent in a regulated or high-risk context. The correct output should remain complete and useful without promotional content.

Version the event contract, template, policy, and renderer together. That is what makes a generated transactional email reproducible when a customer asks what happened.