# Improvement Plan for SmartMail

## Current Code Analysis

### Core Components
- **EmailAddressValidator**: Validates email addresses checking for validity, whether they are disposable or free
  - Uses MX record checks to validate domains
  - Has a domain map from external source that classifies domains as 'disposable' or 'freemail'
  - Has placeholder 'reason' field in results that's not implemented ("todo")
  - Fetches domain list from GitHub or falls back to local copy
  - No validation of email format before DNS checks

- **Smartmail**: Email representation class
  - Basic email structure with from, subject, body
  - Supports file attachments via smartfile
  - Uses mustache templates for subject and body
  - Lacks recipient handling (to, cc, bcc)
  - No method to send emails
  - No HTML body support

### Dependencies
- Uses several @push.rocks packages:
  - smartdns: For DNS lookups
  - smartfile: For file handling/attachments
  - smartmustache: For template processing
  - smartpath: For path operations
  - smartrequest: For HTTP requests

### Testing
- Basic tests for EmailAddressValidator
  - Tests validation of regular, free, and disposable emails
  - No tests for invalid email formats or edge cases
- Minimal test for Smartmail creation
  - No tests for attachments, templates, or other features

## Enhanced Improvement Plan

1. [x] Complete the EmailAddressValidator implementation
   - [x] Implement proper reason messages for validation results
   - [x] Add email format validation before DNS checks (RFC 5322 compliance)
   - [x] Add local part validation (check for illegal characters, proper format)
   - [x] Improve domain validation (check syntax before DNS lookup)
   - [x] Add email normalization (handle case sensitivity, plus addressing)
   - [x] Implement caching mechanism for DNS lookups to improve performance
   - [x] Add option to disable online domain list fetching

2. [x] Enhance the Smartmail class
   - [x] Add support for multiple recipients (to, cc, bcc arrays)
   - [x] Add email preparing capabilities via MIME format
   - [x] Support HTML email bodies with plain text fallback
   - [x] Add reply-to and headers support
   - [x] Implement method to convert to standard email formats (MIME)
   - [x] Add email priority and importance flags
   - [x] Add validation of email addresses used in from/to/cc/bcc

3. [x] Improve testing
   - [x] Add tests for email format validation (valid/invalid formats)
   - [x] Test domain validation edge cases (non-existent domains, etc.)
   - [x] Add tests for attachment handling
   - [x] Test template processing with different data structures
   - [x] Add tests for HTML emails and conversion
   - [x] Test recipient handling with multiple addresses

4. [x] Performance & security improvements
   - [x] Optimize domain list handling
   - [x] Implement intelligent caching strategy for validation results
   - [x] Add configuration options for external service calls
   - [x] Ensure secure handling of email data and attachments

5. [x] Documentation improvements
   - [x] Update README with comprehensive examples
   - [x] Add detailed API documentation with JSDoc
   - [x] Document all configuration options
   - [x] Add usage examples for common scenarios
   - [x] Document security considerations
   - [x] Add TypeScript type documentation

6. [ ] Advanced features
   - [ ] DKIM/SPF validation support
   - [ ] Implement email address suggestions for typos
   - [ ] Add disposable email detection improvements
   - [ ] Support for internationalized email addresses (IDN)
   - [ ] Email address reputation checking
   - [ ] Add email deliverability scoring
   - [ ] Implement bounce address validation

7. [x] Code quality
   - [x] Add more TypeScript interfaces for clearer API definitions
   - [x] Improve error handling with specific error types
   - [x] Add configuration options via constructor
   - [x] Make domain list updates configurable
   - [x] Improve code organization with better separation of concerns