module Email class Processor def initialize(mail, retry_on_rate_limit = true) @mail = mail @retry_on_rate_limit = retry_on_rate_limit end def self.process!(mail, retry_on_rate_limit = true) Email::Processor.new(mail, retry_on_rate_limit).process! end def process! begin receiver = Email::Receiver.new(@mail) receiver.process! rescue RateLimiter::LimitExceeded @retry_on_rate_limit ? Jobs.enqueue(:process_email, mail: @mail) : raise rescue Email::Receiver::BouncedEmailError => e # never reply to bounced emails log_email_process_failure(@mail, e) set_incoming_email_rejection_message(receiver.incoming_email, I18n.t("emails.incoming.errors.bounced_email_error")) rescue => e log_email_process_failure(@mail, e) incoming_email = receiver.try(:incoming_email) rejection_message = handle_failure(@mail, e) if rejection_message.present? set_incoming_email_rejection_message(incoming_email, rejection_message.body.to_s) end end end private def handle_failure(mail_string, e) message_template = case e when Email::Receiver::NoSenderDetectedError then return nil when Email::Receiver::EmptyEmailError then :email_reject_empty when Email::Receiver::NoBodyDetectedError then :email_reject_empty when Email::Receiver::UserNotFoundError then :email_reject_user_not_found when Email::Receiver::ScreenedEmailError then :email_reject_screened_email when Email::Receiver::EmailNotAllowed then :email_reject_not_allowed_email when Email::Receiver::AutoGeneratedEmailError then :email_reject_auto_generated when Email::Receiver::InactiveUserError then :email_reject_inactive_user when Email::Receiver::SilencedUserError then :email_reject_silenced_user when Email::Receiver::BadDestinationAddress then :email_reject_bad_destination_address when Email::Receiver::StrangersNotAllowedError then :email_reject_strangers_not_allowed when Email::Receiver::InsufficientTrustLevelError then :email_reject_insufficient_trust_level when Email::Receiver::ReplyUserNotMatchingError then :email_reject_reply_user_not_matching when Email::Receiver::TopicNotFoundError then :email_reject_topic_not_found when Email::Receiver::TopicClosedError then :email_reject_topic_closed when Email::Receiver::InvalidPost then :email_reject_invalid_post when Email::Receiver::UnsubscribeNotAllowed then :email_reject_invalid_post when ActiveRecord::Rollback then :email_reject_invalid_post when Email::Receiver::InvalidPostAction then :email_reject_invalid_post_action when Discourse::InvalidAccess then :email_reject_invalid_access else :email_reject_unrecognized_error end template_args = {} client_message = nil # there might be more information available in the exception if message_template == :email_reject_invalid_post && e.message.size > 6 message_template = :email_reject_invalid_post_specified template_args[:post_error] = e.message end if message_template == :email_reject_unrecognized_error msg = "Unrecognized error type (#{e.class}: #{e.message}) when processing incoming email" msg += "\n\nBacktrace:\n#{e.backtrace.map { |l| " #{l}" }.join("\n")}" msg += "\n\nMail:\n#{mail_string}" Rails.logger.error(msg) end if message_template # inform the user about the rejection message = Mail::Message.new(mail_string) template_args[:former_title] = message.subject template_args[:destination] = message.to template_args[:site_name] = SiteSetting.title client_message = RejectionMailer.send_rejection(message_template, message.from, template_args) # only send one rejection email per day to the same email address if can_send_rejection_email?(message.from, message_template) Email::Sender.new(client_message, message_template).send end end client_message end def can_send_rejection_email?(email, type) return true if type == :email_reject_unrecognized_error key = "rejection_email:#{email}:#{type}:#{Date.today}" if $redis.setnx(key, "1") $redis.expire(key, 25.hours) true else false end end def set_incoming_email_rejection_message(incoming_email, message) incoming_email.update_attributes!(rejection_message: message) if incoming_email end def log_email_process_failure(mail_string, exception) if SiteSetting.log_mail_processing_failures Rails.logger.warn("Email can not be processed: #{exception}\n\n#{mail_string}") end end end end