Mailgate: Proper rights assignment to allow everybody to submit tickets

We have been using RT for a while now, and just recently we upgraded to 3.4.1. Nevertheless I am still very confused on getting the rights assignments in order to achieve the following. I will refer to one QUEUE only in this description, although we do have several queues for different purposes.
everybody should be able to submit tickets by e-mail, to a specific queue.
New users should be automatically be created and get the right to see their tickets and reply to them (ShowTicket and ReplyToTicket)
They shall NOT have the right to own tickets !
They should be able to use the “self service” web interface.
It seams quite straightforward.
The problem we are having, is that all users somehow get the (OwnTicket) right, and hence show up on the “Owner Drop Down” on the Peoples page. This makes the interface behave very slowly and besides there are only about 20 people that can own tickets (Call Center and Support personnel) but there are a couple thousand and growing customers that can and should be requestor’s only.

I do appreciate any help in advance,

Regards,

Manfred Koroschetz

It seams quite straightforward.

The problem we are having, is that all users somehow get the (OwnTicket)
right, and hence show up on the “Owner Drop Down” on the Peoples page. This
makes the interface behave very slowly and besides there are only about 20
people that can own tickets (Call Center and Support personnel) but there are
a couple thousand and growing customers that can and should be requestor’s
only.

It’s as simple as you think it is. Make sure that you didn’t grant the
own ticket right to Everyone or to Unprivledged users. Make sure the
users are created unprivledged (that’s the default). Remember that
you’ve got both the queue acl, and the global acl.

seph