Download a list of all users and their email addresses in a Slack group.
Python 2.7+
pip install slacker
Enter your API key in the appropriate place in the script.
From the command line, browse to the script directory and run:
python emails.py
The output is simply printed to stdout in CSV format. Future versions of the script could allow an option to output directly to a file.
This will only return users who have their email address available in their profile.