func (sof *RelayOnlyFilter) Filter(mail mailfile.Mail) Result { log.Printf("Run %s, Mail:%s\n", sof, mail.Name()) sof.total.Inc(1) sendOut := false for _, address := range mail.To() { if !strings.HasSuffix(address.Address, sof.localDomain) { sendOut = true sof.numOfRelay.Inc(1) break } } if !sendOut { return Incoming } return sof.next.Filter(mail) }