We’ve not had much luck with triggering the salesforce native email tools. This may be a case where you need to go with an external email tool like Marketo.
You basically need to create a model for object C that gets queried whenever a new row in Model B is created. (Model Action probably)
Then the rows in Model C need to get passed into the external email generation tool
Here is a post Zach wrote about mass email using Marketo. https://community.skuid.com/t/how-to-add-marketo-send-email-mass-action-to-a-skuid-tab…
