delivery extension

• 传递扩展插件

delivery extension的用法和样例：

例句

1. Delivery extensions work in conjunction with subscriptions.
   传递扩展插件可以与订阅协同工作。
2. The default e-mail delivery extension does not provide support for digitally signing or encrypting outgoing mail messages.
   默认电子邮件传递扩展插件不支持给待发邮件进行数字签名或加密。