[rt-users] deny unexisting users create tickets via email

[mailinglists]

Hi,

I'm sorry if my question is already answered in old posts, but I have 
searched a lot and not found....

People who need RT here, want to provision manually our customers with 
an unique email, and allow only the existing customers to create tickets 
via email.
Other people mailing to operations at mycompagny.com (only one general 
queue) would receive an "unauthorized email" response.
The customers are created as unprivileged, with a password, and  can 
access the SelfService

I studied the following possibilities, but they all have a serious 
drawback, or don't work :

-> revoque the right CreateTicket and SeeQueue for Everyone in the 
General Queue and add it to Unprivileged, but because of AutoCreate, 
when an email is received, the user is provisionned, and become 
unprivileged, and the ticket is created.

-> create a Group "Clients", and allow only privileged users of that 
group to CreateTicket and SeeQueue , but when they login, thez don't get 
only selfservice anymore.

-> I have seen people who play with CanonicalizeOnCreate, AutoCreate, 
SenderMustExistInExternalDatabase, LookupSenderInExternalDatabase in 
RT_SiteConfig but it seem to work only with external authentication  
(http://lists.bestpractical.com/pipermail/rt-users/2003-February/012029.html)

It appears to as a basic config, I can't believe that nobody had the 
same need, and has found or developped solution !

Thank you very much for help

laetib