欠资邮件 meaning in English

postage due mails

If the registered mail or postage due mail can not be delivered in the manner illustrated above , further actions taken should follow the provisions specified under article 48 hereof
挂号邮件及欠资邮件无法依前项规定投递者，依第四十八条所订之规则有关投递规定办理。
Where there is no doorman or receptionist but only mail boxes , intercoms or door bells on the ground floor , ordinary mail items may be dropped in the mail box , and the addressee may be asked via intercom or ringing of the bell to come to the ground floor for pickup of registered mail or to pay postage due
二无法依前款规定投递、地面层未设有管理服务人员或邮件收发处而仅设置受信设备、对讲机或电铃者，平常邮件投入受信设备，挂号邮件及欠资邮件，请收件人至地面层领取或补付欠资。