module ActionMailbox::InboundEmail::MessageId extend ActiveSupport::Concern included do before_save :generate_missing_message_id end module ClassMethods def create_and_extract_message_id!(source, **options) create! message_id: extract_message_id(source), **options do |inbound_email| inbound_email.raw_email.attach io: StringIO.new(source), filename: "message.eml", content_type: "message/rfc822" end end private def extract_message_id(source) mail_from_source(source).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