Email CSM when ticket moved to urgent

I am looking to send a single notification to a CSM of an Organization if a case priority is set to urgent. 

I have a Org field that looks up to user to set the CSM.

I have tried:

1. using placeholders, whcich didnt seem to capture the email with this tag:  {{ticket.organization.custom_fields.csm_test_with_stephen.email}}

2. use triggers to set the CSM on a ticket and then a trigger to send a notification. The problem is this requires a rule per CSM to set the ticket value

Is there a simpler way to do this? I feel I am missing something here.