Mailman Problem

[duvide]

I set up a Mailman list on Plesk 12.0.18 at one domain of my server like let's say here:

http://list.xxx.de/mailman/admin/mailman

When I want to edit the list of the subscribers it still looks normal:

http://list.xxx.de/mailman/admin/mailman/members

But when I want to find members in the list with "search" I get a not found page and the URL is:

http://lists.v123.1blu.de/mailman/admin/mailman/members?letter=1

it changes to the host server name. That also happens when I click on 1, 2, a, b, c, ...

What can I do? I already refreshed and cleaned the cache and deleted cookies in the browser.

 

[duvide]

... by now I figured out that the list has to be created in Plesk in a user account for the domain.
Then the administration will be done in Mailman. All the links work then.
But I can not send out mails, not even the invitation mails go out. I googled for this problem and found this here:
http://wiki.list.org/DOC/4.78 Troubleshooting- No mail going out to lists members
and here no. 2 in particular:

1. Mailman 2.1.x - Later versions of Mailman, versions 2.1 and above, need cron for certain support jobs, but not for normal mail delivery. In Mailman 2.1.x there is an independent daemon called mailmanctl. You need to make sure that the mailmanctl daemon is also running
   ps auxww| grep mailmanctl |grep -v grep
   If this returns a blank line then the Mailman daemon is not running! Also, do
   ps auxww | egrep 'p[y]thon'
   or
   ps -fAww | egrep 'p[y]thon'
   or however you might spell it on your system. This should show that mailmanctl and eight qrunner processes are all running. See item 6. below.

I seems mailmanctl and eight qrunner processes are not running on my server.
In my /var/log/mailman/error I also have this:

Aug 02 04:46:26 2015 mailmanctl(31985): PID in /var/run/mailman/master-qrunner.pid nicht lesbar
Aug 02 04:46:26 2015 mailmanctl(31985): [Errno 2] No such file or directory: '/var/run/mailman/master-qrunner.pid'
Aug 02 04:46:26 2015 mailmanctl(31985): Läuft qrunner überhaupt?

This is what the wiki further says about the qrunner:

Mailman 2.1.x - If you are running Mailman 2.1.x then the qrunners are daemons that are started by $prefix/bin/mailmanctl, which itself may be being run via a 'mailman' startup script. This is described in the INSTALL document for the version of MM you are running. Note that there are eight qrunners...

But I don't know what to do about it.
Any help?