Hi Andy,
Is it a modified customer transaction type (ZMIN) or standard one?
You can maintain this in Action Profiles. Transaction SPPFCADM, choose 'CRM ORDER', and click on 'Condition Configuration' button.
Choose Incident Management Message (for SMIN), for ZMIN it will Z Incident Management Message.
Click on 'Create' button, and choose 'E-mail to Reporter'
For newly created Action, choose 'Start condition' tab and clikc on 'Edit Condition' button.
Give a Name for your new Action, and after that maintain condition.
Click on 'Click here to create a new condition'
Choose 'User Status' for Express. 1 column, in Operator column choose '=', and then in Constant tab choose appropriate User Status - Customer Action for Express. 2 column.
After that save Condition and go back.
It should work.