UofT Outlook Skill

Headless access to University of Toronto alumni/student Outlook via IMAP/SMTP with OAuth2.

Trit: -1 (MINUS - validator/consumer) Principle: Thunderbird Client ID → Device Code Auth → Keychain Cache → IMAP/SMTP Implementation: IMAP OAuth2 (XOAUTH2) + Thunderbird Pre-Authorized Client ID

The AADSTS65002 Problem

University tenants block third-party OAuth apps:

AADSTS65002: Consent between first party application and first party resource 
must be configured via preauthorization

Solution: Use Thunderbird's pre-authorized client ID 9e5f94bc-e8a4-4e73-b8be-63364c29d753 which Microsoft has pre-approved for IMAP/SMTP access on all tenants.

Authentication Architecture

┌─────────────────────────────────────────────────────────────────────┐
│               THUNDERBIRD CLIENT ID BYPASS                          │
├─────────────────────────────────────────────────────────────────────┤
│                                                                     │
│  [Problem: Graph API blocked]                                       │
│  ┌──────────┐     Graph API      ┌───────────────┐                 │
│  │  Agent   │ ────────────────▶  │ MS Entra ID   │                 │
│  └──────────┘                    └───────────────┘                 │
│       │                                 │                           │
│       │                                 ▼                           │
│       │                    ❌ AADSTS65002 Error                     │
│       │                    "Admin consent required"                 │
│                                                                     │
│  [Solution: Thunderbird IMAP]                                       │
│  ┌──────────┐  Thunderbird ID    ┌───────────────┐                 │
│  │  Agent   │ ─────────────────▶ │ MS Entra ID   │                 │
│  └──────────┘  9e5f94bc-...      └───────────────┘                 │
│       │                                 │                           │
│       │ Device code flow                │ Pre-authorized ✓         │
│       ▼                                 ▼                           │
│  "Enter code XXXXXX at microsoft.com/devicelogin"                  │
│       │                                                             │
│       │ User authenticates (one-time)                               │
│       ▼                                                             │
│  ┌──────────────────────────────────────────────────┐              │
│  │           macOS Keychain (secure storage)        │              │
│  │  outlook-university: access + refresh tokens    │              │
│  └──────────────────────────────────────────────────┘              │
│       │                                                             │
│       │ XOAUTH2 authentication                                      │
│       ▼                                                             │
│  ┌───────────────────────────────────────────────┐                 │
│  │  outlook.office365.com:993 (IMAP)             │                 │
│  │  smtp.office365.com:587 (SMTP)                │                 │
│  └───────────────────────────────────────────────┘                 │
└─────────────────────────────────────────────────────────────────────┘

Key Constants

# Thunderbird's pre-authorized client ID (public, safe to commit)
THUNDERBIRD_CLIENT_ID = "9e5f94bc-e8a4-4e73-b8be-63364c29d753"

# IMAP OAuth2 scopes (NOT Graph API scopes!)
IMAP_SCOPES = [
    "https://outlook.office.com/IMAP.AccessAsUser.All",
    "https://outlook.office.com/SMTP.Send",
    "offline_access",
    "openid", "profile", "email"
]

# Servers
IMAP_SERVER = "outlook.office365.com"  # Port 993 SSL
SMTP_SERVER = "smtp.office365.com"      # Port 587 STARTTLS

Usage

Initial Authentication (One-Time)

cd ~/.claude/skills/utoronto-outlook
uv run python outlook_university.py auth

# Output:
# ============================================================
# OUTLOOK UNIVERSITY - DEVICE CODE AUTHENTICATION
# ============================================================
#   Code: XXXXXXXXX
#   Go to: https://microsoft.com/devicelogin
#   (Uses Thunderbird's pre-authorized client ID)
# ============================================================

Headless Operations

# Check login
uv run python outlook_university.py whoami
# Logged in as: [email protected]

# List messages
uv run python outlook_university.py list 10

# Read message
uv run python outlook_university.py read 42

# Search
uv run python outlook_university.py search "professor"

# List folders
uv run python outlook_university.py folders

Python API

from outlook_university import OutlookClient

client = OutlookClient()

# List recent emails
messages = client.list_messages(limit=10)

# Get unread
unread = client.get_unread()

# Read full message (body truncated to 2000 chars for context safety)
msg = client.get_message("42")

# Search
results = client.search("grades")

# Send email
client.send(
    to=["[email protected]"],
    subject="Test",
    body="Hello from headless Outlook!"
)

client.close()

XOAUTH2 Authentication

The critical implementation detail for IMAP OAuth2:

# Build XOAUTH2 string per RFC 7628
auth_string = f"user={email}\x01auth=Bearer {access_token}\x01\x01"

# IMAP authenticate callback returns raw bytes
conn.authenticate("XOAUTH2", lambda x: auth_string.encode())

GF(3) Verb Typing

Security Notes

• Thunderbird Client ID: Public, safe to commit (used by Mozilla Thunderbird)
• Tokens: Stored in macOS Keychain (encrypted), never in files
• Body Truncation: Email bodies truncated to 2000 chars to prevent context overflow
• No Credentials: No passwords stored; OAuth2 refresh tokens only
• Terminal Sanitization: ANSI escape codes stripped from output