Write a Transactional Email Suite

Write the full suite of transactional emails for the following product:

Product type: [SaaS / e-commerce / marketplace / membership]
Brand tone: [e.g. warm / professional / minimalist]
Key user actions that trigger emails: [list the triggers]

Write copy for each transactional email:

1. Email confirmation / OTP: clear, fast, one action
2. Welcome (after email confirmed): first thing they should do
3. Password reset: clear instructions, expires in [X hours]
4. Payment successful: what they paid for, receipt details, next step
5. Payment failed: non-alarming, clear action to fix
6. Subscription renewal reminder (7 days before): friendly heads up
7. Account about to be deleted / downgraded: retention without desperation
8. Invoice / receipt: what to include for business users

For each email:
- Subject line (clear and functional — transactional emails should be easy to find)
- Preview text
- Body (minimal — every word has a job)
- CTA button text
- Footer requirements (unsubscribe note, company address)