outlook-delegate

# Outlook Delegate Skill

Access another user's Outlook/Microsoft 365 email and calendar as a **delegate** via Microsoft Graph API. Supports three sending modes: as yourself, as the owner, or on behalf of the owner.

## Delegate Architecture

This skill is designed for scenarios where:
- **Your AI assistant** (the delegate) has its own Microsoft 365 account
- **The owner** has granted the assistant delegate access to their mailbox/calendar
- The assistant can send emails as itself, as the owner, or on behalf of the owner

### Sending Modes Explained

All three modes use the same Graph API call (`/users/{delegate}/sendMail` with the `from` field set). **The difference between Send As and Send on Behalf is determined entirely by which Exchange permission is granted**, not by the API endpoint.

| Mode | Command | Exchange Permission Required | `from` field | `sender` field | What Recipient Sees |
|------|---------|------------------------------|--------------|----------------|---------------------|
| As Self | `send` | (none extra) | Delegate | Delegate | "From: Assistant" |
| As Owner (Send As) | `send-as` | **SendAs only** | Owner | Owner | "From: Owner" |
| On Behalf Of | `send-behalf` | **SendOnBehalf only** | Owner | Delegate | "From: Assistant on behalf of Owner" |

> **⚠️ CRITICAL:** Do NOT grant both SendAs and SendOnBehalf permissions. If both are granted, Exchange always uses SendAs, and the "on behalf of" indication will never appear. Choose ONE based on your desired behavior.

### How It Works Under the Hood

When you call `send-as` or `send-behalf`, the skill makes the same API call: it sends via the delegate's endpoint with the owner in the `from` field. Microsoft Graph automatically sets the `sender` property to the authenticated user (the delegate). Whether the recipient sees "on behalf of" depends solely on the Exchange permission:

- **SendAs permission** → Graph sets both `sender` and `from` to the owner. No indication of delegation.
- **SendOnBehalf...