Several Mailman features occur on a regular schedule, so you must set up cron to run the right programs at the right time6.
If your version of crontab supports the -u option, you must be root to do this next step. Add $prefix/cron/crontab.in as a crontab entry by executing these commands:
    % cd $prefix/cron
    % crontab -u mailman crontab.in
If you used the --with-username option, use that user name
instead of mailman for the -u argument value.  If your
crontab does not support the -u option, try these commands:
    % cd $prefix/cron
    % su - mailman
    % crontab crontab.in
    MAILTO=user@example.com
or
    MAILTO=mailman-owner
at the beginning of crontab.in before installing it to cause this output to be mailed to a real user or to the owner of the site list or to configure the site list (see section 8) to accept this mail.