Ephemeral Email API Instructions:

Authentication:
All requests require an API key in the Authorization header:
Authorization: Bearer demo-api-key-2024

Endpoints:
1. Create a new mailbox (two options):
   POST /mail
   GET /mail/new
   Both accept optional parameters:
   - POST: JSON body with { "label": "string", "notes": "string" }
   - GET: Query params ?label=string&notes=string
   Returns: { mailboxId: string, email: string, label?: string, notes?: string }

2. Check mailbox messages:
   GET /mail/inbox/:id
   Returns: Array of messages or 404 if invalid

Note: This is a prototype system - emails persist only in memory.