After installing Mailman 2.1.8 and configuring Apache and Postfix, I had the following error message when creating a new list from the web interface. Nothing online seemed to provide the right answer. But since I've managed to figure what exactly was the problem, I thought I'd share with the community.

RuntimeError: command failed: /usr/sbin/postmap /usr/local/mailman/data/virtual-mailman (status: 1, Operation not permitted)

I followed the online installation instructions to create the new "mailman" mailing list via command line:

http://www.gnu.org/software/mailman/mailman-install/node40.html

% bin/newlist mailman

But I think when I ran that newlist command as the mailman user, it generated the virtual-mailman.db file in the data directory such that it was owned by the mailman user. Since my data directory has drwxrwsr-x permissions, the www user could not recreate the virtual-mailman.db file when I made a new list via the web interface.

I corrected the problem by making the virtual-mailman.db file be owned by the www user:

chown www virtual-mailman.db

I hope this hint helps some poor soul out there. Maybe this can be noted in the postfix section of the installation manual.

Louie