Requirements

Binaries:

• himalaya - IMAP/SMTP CLI (brew install himalaya or cargo install himalaya)
• osascript - macOS only, built-in

Credentials:

• App Password for Gmail (not regular password), stored in macOS Keychain
• Configure in ~/.config/himalaya/config.toml

Data Access

Read-only paths:

• ~/Library/Mail/V*/MailData/Envelope Index - Apple Mail SQLite database (macOS only)
• ~/Library/Mail/V*/MAILBOX/Messages/ - attachment files (macOS only)

Scope

This skill:

• ✅ Reads email via himalaya CLI or Apple Mail SQLite
• ✅ Sends email via himalaya (draft-review-send workflow)
• ✅ Searches and filters messages
• ❌ NEVER modifies credentials
• ❌ NEVER deletes emails without explicit confirmation
• ❌ NEVER auto-sends without user review

Quick Reference

Core Rules

1. Platform Detection

• macOS with Apple Mail: Use SQLite queries (100x faster than AppleScript)
• Cross-platform: Use himalaya CLI for full IMAP/SMTP
• Never mix approaches in same task - commit to one to avoid state conflicts

2. Apple Mail SQLite

• Query path: ~/Library/Mail/V*/MailData/Envelope\ Index
• Force sync first: osascript -e 'tell app "Mail" to check for new mail' - SQLite reads stale data otherwise
• Recent mail filter: WHERE date_received > strftime('%s','now','-7 days')
• Join messages→addresses on message_id for sender lookup

3. himalaya CLI

• Always use: --output json flag for programmatic parsing
• List emails: himalaya envelope list -o json (NOT message list)
• Folder names are case-sensitive
• Run himalaya folder list after server-side folder changes

4. Send Protocol

• Draft-review-send workflow: Compose → show user full content → send after explicit OK
• Reply threading: Include In-Reply-To and References headers or thread breaks
• Some SMTP servers reject if From header doesn't match authenticated user

5. Credential Management

• macOS Keychain: security add-internet-password -s imap.gmail.com -a user@gmail.com -w 'app-password'
• Gmail/Google Workspace: Requires App Password with 2FA enabled
• OAuth: himalaya supports XOAUTH2 via token_cmd in config.toml

6. Thread Intelligence

• Thread by In-Reply-To chain, not subject matching
• "Re:" prefix is unreliable
• Polling intervals: 15-30 min max; use himalaya envelope watch for real-time