Transition from SLFN to SMIN

Hello,

how can I do the transition from SLFN to SMIN?

I want to have the possibility to process existing SLFN messages until they are closed and I want to restrict the way of opening messages only to the new transaction type SMIN.

I read that this is possible via authorization but is it possible to do it only in a technical way? To set in SolMan "if creation of a new support message use always type SMIN"?

Thanks for you help

BR

Tanja