allows unfeasible emails only to be send out once

app/models/spending_proposal.rb

@@ -69,15 +69,24 @@ class SpendingProposal < ActiveRecord::Base
   end
 
   def marked_as_unfeasible?
-    previous_changes.has_key?("feasible") && unfeasible?
+    unfeasible_email_sent_at.blank? && unfeasible? && valuation_finished?
   end
 
   def unfeasible?
     not feasible?
   end
 
+  def valuation_finished?
+    valuation_finished
+  end
+
   def code
     "#{id}" + (administrator.present? ? "-A#{administrator.id}" : "")
   end
 
+  def send_unfeasible_email
+    Mailer.unfeasible_spending_proposal(self).deliver_later
+    update(unfeasible_email_sent_at: Time.now)
+  end
+
 end