module ActionMailroom::InboundEmail::MessageId extend ActiveSupport::Concern included do before_save :generate_missing_message_id end module ClassMethods def create_and_extract_message_id!(raw_email, **options) create! raw_email: raw_email, message_id: extract_message_id(raw_email), **options end private def extract_message_id(raw_email) mail_from_source(raw_email.read).message_id rescue => e # FIXME: Add logging with "Couldn't extract Message ID, so will generating a new random ID instead" end end private def generate_missing_message_id self.message_id ||= Mail::MessageIdField.new.message_id end end