FEATURE: new 'enable_forwarded_email' site setting

Gemfile

@@ -66,7 +66,7 @@ gem 'aws-sdk', require: false
 gem 'excon', require: false
 gem 'unf', require: false
 
-gem 'email_reply_trimmer', '0.1.4'
+gem 'email_reply_trimmer', '0.1.5'
 
 # note: for image_optim to correctly work you need to follow
 # https://github.com/toy/image_optim

Gemfile.lock

@@ -80,7 +80,7 @@ GEM
     docile (1.1.5)
     domain_name (0.5.25)
       unf (>= 0.0.5, < 1.0.0)
-    email_reply_trimmer (0.1.4)
+    email_reply_trimmer (0.1.5)
     ember-data-source (1.0.0.beta.16.1)
       ember-source (~> 1.8)
     ember-handlebars-template (0.7.3)
@@ -411,7 +411,7 @@ DEPENDENCIES
   certified
   discourse-qunit-rails
   discourse_fastimage (= 2.0.3)
-  email_reply_trimmer (= 0.1.4)
+  email_reply_trimmer (= 0.1.5)
   ember-rails (= 0.18.5)
   ember-source (= 1.12.2)
   excon

config/locales/server.en.yml

@@ -1246,6 +1246,8 @@ en:
     attachment_content_type_blacklist: "List of keywords used to blacklist attachments based on the content type."
     attachment_filename_blacklist: "List of keywords used to blacklist attachments based on the filename."
 
+    enable_forwarded_emails: "[BETA] Allow users to create a topic by forwarding an email in."
+
     manual_polling_enabled: "Push emails using the API for email replies."
     pop3_polling_enabled: "Poll via POP3 for email replies."
     pop3_polling_ssl: "Use SSL while connecting to the POP3 server. (Recommended)"

config/site_settings.yml

@@ -670,7 +670,7 @@ email:
   attachment_filename_blacklist:
     type: list
     default: "smime.p7s|signature.asc"
-
+  enable_forwarded_emails: false
 
 files:
   max_image_size_kb:

lib/email/receiver.rb

@@ -38,7 +38,7 @@ module Email
 
     def process!
       return if is_blacklisted?
-      @from_email, @from_display_name = parse_from_field
+      @from_email, @from_display_name = parse_from_field(@mail)
       @incoming_email = find_or_create_incoming_email
       process_internal
     rescue => e
@@ -74,7 +74,7 @@ module Email
       raise InactiveUserError if !user.active && !user.staged
       raise BlockedUserError  if user.blocked
 
-      body, @elided = select_body
+      body, elided = select_body
       body ||= ""
 
       raise NoBodyDetectedError if body.blank? && attachments.empty?
@@ -90,6 +90,7 @@ module Email
       elsif post = find_related_post
         create_reply(user: user,
                      raw: body,
+                     elided: elided,
                      post: post,
                      topic: post.topic,
                      skip_validations: user.staged?)
@@ -98,7 +99,7 @@ module Email
 
         destinations.each do |destination|
           begin
-            process_destination(destination, user, body)
+            process_destination(destination, user, body, elided)
           rescue => e
             first_exception ||= e
           else
@@ -237,16 +238,19 @@ module Email
       reply.split(previous_replies_regex)[0]
     end
 
-    def parse_from_field
+    def parse_from_field(mail)
-      if @mail[:from].errors.blank?
+      if mail[:from].errors.blank?
-        address_field = @mail[:from].address_list.addresses.first
+        mail[:from].address_list.addresses.each do |address_field|
           address_field.decoded
           from_address = address_field.address
           from_display_name = address_field.display_name.try(:to_s)
-      else
+          return [from_address.downcase, from_display_name] if from_address["@"]
-        from_address = @mail.from[/<([^>]+)>/, 1]
-        from_display_name = @mail.from[/^([^<]+)/, 1]
         end
+      end
+
+      from_address = mail.from[/<([^>]+)>/, 1]
+      from_display_name = mail.from[/^([^<]+)/, 1]
+
       [from_address.downcase, from_display_name]
     end
 
@@ -314,12 +318,17 @@ module Email
       end
     end
 
-    def process_destination(destination, user, body)
+    def process_destination(destination, user, body, elided)
+      return if SiteSetting.enable_forwarded_emails &&
+                has_been_forwarded? &&
+                process_forwarded_email(destination, user)
+
       case destination[:type]
       when :group
         group = destination[:obj]
         create_topic(user: user,
                      raw: body,
+                     elided: elided,
                      title: subject,
                      archetype: Archetype.private_message,
                      target_group_names: [group.name],
@@ -347,11 +356,69 @@ module Email
 
         create_reply(user: user,
                      raw: body,
+                     elided: elided,
                      post: email_log.post,
                      topic: email_log.post.topic)
       end
     end
 
+    def has_been_forwarded?
+      subject[/^[[:blank]]*(re|fwd?)[[:blank]]?:/i] && embedded_email_raw.present?
+    end
+
+    def embedded_email_raw
+      return @embedded_email_raw if @embedded_email_raw
+      text = fix_charset(@mail.multipart? ? @mail.text_part : @mail)
+      @embedded_email_raw, @before_embedded = EmailReplyTrimmer.extract_embedded_email(text)
+      @embedded_email_raw
+    end
+
+    def process_forwarded_email(destination, user)
+      embedded = Mail.new(@embedded_email_raw)
+      email, display_name = parse_from_field(embedded)
+      embedded_user = find_or_create_user(email, display_name)
+      raw = embedded.decoded
+      title = embedded.subject.presence || subject
+
+      case destination[:type]
+      when :group
+        group = destination[:obj]
+        post = create_topic(user: embedded_user,
+                            raw: raw,
+                            title: title,
+                            archetype: Archetype.private_message,
+                            target_group_names: [group.name],
+                            is_group_message: true,
+                            skip_validations: true,
+                            created_at: embedded.date)
+
+      when :category
+        category = destination[:obj]
+
+        return false if user.staged? && !category.email_in_allow_strangers
+        return false if !user.has_trust_level?(SiteSetting.email_in_min_trust)
+
+        post = create_topic(user: embedded_user,
+                            raw: raw,
+                            title: title,
+                            category: category.id,
+                            skip_validations: embedded_user.staged?,
+                            created_at: embedded.date)
+      else
+        return false
+      end
+
+      if post && post.topic && @before_embedded.present?
+        create_reply(user: user,
+                     raw: @before_embedded,
+                     post: post,
+                     topic: post.topic,
+                     post_type: Post.types[:whisper])
+      end
+
+      true
+    end
+
     def reply_by_email_address_regex
       @reply_by_email_address_regex ||= begin
         reply_addresses = [
@@ -483,16 +550,17 @@ module Email
       options[:raw_email] = @raw_email
 
       # ensure posts aren't created in the future
-      options[:created_at] = [@mail.date, DateTime.now].min
+      options[:created_at] ||= @mail.date
+      options[:created_at]   = DateTime.now if options[:created_at] > DateTime.now
 
       is_private_message = options[:archetype] == Archetype.private_message ||
                            options[:topic].try(:private_message?)
 
       # only add elided part in messages
-      if @elided.present? && is_private_message
+      if options[:elided].present? && is_private_message
         options[:raw] << "\n\n" << "<details class='elided'>" << "\n"
         options[:raw] << "<summary title='#{I18n.t('emails.incoming.show_trimmed_content')}'>&#183;&#183;&#183;</summary>" << "\n"
-        options[:raw] << @elided << "\n"
+        options[:raw] << options[:elided] << "\n"
         options[:raw] << "</details>" << "\n"
       end
 
@@ -508,6 +576,8 @@ module Email
           add_other_addresses(result.post.topic, user)
         end
       end
+
+      result.post
     end
 
     def add_other_addresses(topic, sender)
@@ -518,6 +588,7 @@ module Email
               address_field.decoded
               email = address_field.address.downcase
               display_name = address_field.display_name.try(:to_s)
+              next unless email["@"]
               if should_invite?(email)
                 user = find_or_create_user(email, display_name)
                 if user && can_invite?(topic, user)