winmail2ics

Extract iCal from winmail.dat (TNEF) files with Russian encoding support.

Features

• Parse Microsoft Outlook TNEF/winmail.dat attachments
• Handle CP1251, KOI8-R, and other Russian character encodings
• Generate Mac-compatible iCal (.ics) files with proper timezone support
• Auto-detect timezone from meeting data (e.g., "Asia/Novosibirsk")
• Double-click integration via macOS app bundle

Installation

Requires uv:

# Install uv if not already installed
curl -LsSf https://astral.sh/uv/install.sh | sh

# Clone/download this project, then install globally:
cd winmaiil
uv tool install .

This installs winmail2ics command globally in ~/.local/bin/.

Usage

Command Line

# Basic usage - creates .ics file in same folder
winmail2ics winmail.dat

# Specify output file
winmail2ics winmail.dat -o meeting.ics

# Override timezone
winmail2ics winmail.dat --tz Europe/Moscow

# Quiet mode (no meeting details printed)
winmail2ics winmail.dat -q

Double-Click Integration (macOS)

Build and install the native app:

cd winmaiil
uv run pyinstaller winmail2ical.spec --clean --noconfirm
cp -r dist/Winmail2iCal.app /Applications/
xattr -cr /Applications/Winmail2iCal.app

Then set up file association:

1. Right-click any .dat file → "Get Info" (⌘+I)
2. Under "Open with:", select Winmail2iCal from Applications
3. Click "Change All..." to make it default for all .dat files
4. If Gatekeeper blocks, go to System Settings → Privacy & Security → "Open Anyway"

Dependencies

• tnefparse - TNEF format decoder
• icalendar - iCalendar file generator
• pytz - Timezone handling