Thanks for writing in! I can definitely see the value in automating a mailing based on a deal that's closed in Salesforce. Would that deal be a Salesforce "Opportunity?"
Currently, Emma's Salesforce integration only syncs to Salesforce Lead and Contact records, so while we can trigger an email in response to some Salesforce field changes on those records, I'm afraid we can't yet trigger an email in response to any update that occurs on other Salesforce record types (like Accounts or Opportunities).
We're currently building a brand new autoresponders system that will open up the door to much more sophisticated email automation campaigns, so I'll definitely keep your question in mind. We'd need to update both our autoresponder system and our Salesforce integration to make this possible, so it may be some time before we get there. But I'll be sure to follow up when we do.