[Mailman-Users] Creating a new list - "Bug in Mailman version 2.1.15"

[Kevin Nowaczyk]

I attempted to create a new mailing list on my server via the http://list.myserver.com/create webpage.  The first screen went fine, but upon submitting the list information, I was presented with a large "Bug in Mailman version 2.1.15" page. The mailman error log begins with the line:
Feb 22 12:45:54 2015 (19172) command failed: /usr/sbin/postalias /var/lib/mailman/data/aliases (status: 1, Operation not permitted)

I'm assuming it's a permission problem. If so, what should permissions be, and what files do I need to modify? Do I just need to add the www-data user to the lists group?

Thanks!
Kevin Nowaczyk