Analysis of information sources in references of the Wikipedia article "電子郵箱" in Chinese language version.
In addition to authentication and mailbox location, the mail delivery agent also knows about mailbox quotas which we impose on our subscribers. If the current mailbox size is over the quota for that user, the default being 10 MB, then the message is bounced back to the MTA with reason, "User npc, mailbox full." In addition to preventing resource abuse on the part of subscribers, this also helps mitigate possible damaging effects of mail bombing by malicious people on the Internet. We believe that a 10 MB quota is quite generous, especially considering over a 28.8 modem using very high quality line speeds and no network bottlenecks, one could expect to take over an hour to download the contents of a 10 MB mailbox.[除了认证和邮箱位置之外，邮件递送代理还了解限制我们订阅者的邮箱配额。如果当前的邮箱尺寸超过了给该用户的配额，默认为10MB，那么邮件会被退回消息传输代理，原因是“用户网络参数控制，邮箱已满。”除了阻止对部分订阅者的资源滥用之外，这还有助于抑制因特网上的恶意电邮炸弹可能带来的损害。我们相信，10MB的配额已经很慷慨了，尤其考虑到，即使是非常高质量的网速，也没有网络瓶颈，通过28.8的调制解调器来下载10MB邮箱的内容也要花费一小时以上的时间。]
