Add service for creating invites

app/mailers/notification_mailer.rb

@@ -17,4 +17,10 @@ class NotificationMailer < ApplicationMailer
     @subject = "New app connected to your storage"
     mail to: @user.email, subject: @subject
   end
+
+  def new_invitations_available
+    @user = params[:user]
+    @subject = "New invitations added to your account"
+    mail to: @user.email, subject: @subject
+  end
 end