Do not accept invalid addresses in SMTP RCPT TO

This gives the MTA the chance to inform the original sender
about the transmission error via a delivery report.

lib/foodsoft_mail_receiver.rb

@@ -10,36 +10,45 @@ class FoodsoftMailReceiver < MidiSmtpServer::Smtpd
   end
 
   def self.received(recipient, data)
+    find_handler(recipient).call(data)
+  end
+
+  def start
+    super
+    @handlers = []
+  end
+
+  private
+
+  def on_rcpt_to_event(ctx, rcpt_to)
+    recipient = rcpt_to.gsub(/^\s*<\s*(.*)\s*>\s*$/, '\1')
+    @handlers << self.class.find_handler(recipient)
+    rcpt_to
+  rescue => error
+    raise MidiSmtpServer::Smtpd550Exception
+  end
+
+  def on_message_data_event(ctx)
+    @handlers.each do |handler|
+      handler.call(ctx[:message][:data])
+    end
+    @handlers.clear
+  end
+
+  def self.find_handler(recipient)
     m = /(?<foodcoop>[^@\.]+)\.(?<address>[^@]+)(@(?<hostname>[^@]+))?/.match recipient
     raise "recipient is missing or has an invalid format" if m.nil?
-    raise "Foodcoop '#{m[:foodcoop]}' could not be found" unless FoodsoftConfig.foodcoops.include? m[:foodcoop]
+    raise "Foodcoop '#{m[:foodcoop]}' could not be found" unless FoodsoftConfig.allowed_foodcoop? m[:foodcoop]
     FoodsoftConfig.select_multifoodcoop m[:foodcoop]
 
     @@registered_classes.each do |klass|
-      klass_m = klass.regexp.match(m[:address])
-      return klass.new(klass_m).received(data) if klass_m
+      if match = klass.regexp.match(m[:address])
+        handler = klass.new match
+        return lambda { |data| handler.received(data) }
+      end
     end
 
     raise "invalid format for recipient"
   end
 
-  def start
-    super
-  end
-
-  private
-
-  def on_message_data_event(ctx)
-    puts ctx[:envelope][:to]
-    ctx[:envelope][:to].each do |to|
-      begin
-        m = /<(?<recipient>[^<>]+)>/.match(to)
-        raise "invalid format for RCPT TO" if m.nil?
-        FoodsoftMailReceiver.received(m[:recipient], ctx[:message][:data])
-      rescue => error
-        Rails.logger.warn "Can't deliver mail to #{to}: #{error.message}"
-      end
-    end
-  end
-
 end